Make cast of qualifier explicit (#1276)

Addresses -Wincompatible-pointer-types-discards-qualifiers
compiler warnings.

general/g.parser/translate.c

@@ -12,7 +12,7 @@ char *translate(const char *arg)
     static const char *domain;
 
     if (arg == NULL)
-	return arg;
+	return (char *) arg;
 
     if (strlen(arg) == 0)
         return NULL; /* unset */
@@ -33,6 +33,6 @@ char *translate(const char *arg)
 
     return G_gettext(domain, arg);
 #else
-    return arg;
+    return (char *) arg;
 #endif
 }

lib/imagery/list_subgp.c

@@ -15,7 +15,7 @@
 #include <grass/imagery.h>
 #include <grass/glocale.h>
 
-char **list_subgroups(char *group, const char *mapset, int *subgs_num)
+char **list_subgroups(const char *group, const char *mapset, int *subgs_num)
 {
     /* Unlike I_list_subgroup and I_list_subgroup_simple this function 
        returns array of subgroup names, it does not use fprintf. 

lib/raster/put_row.c

@@ -514,7 +514,7 @@ static void write_null_bits_compressed(const unsigned char *flags,
     compressed_buf = G_malloc(cmax);
 
     /* compress null bits file with LZ4, see lib/gis/compress.h */
-    nwrite = G_compress(flags, size, compressed_buf, cmax, 3);
+    nwrite = G_compress((unsigned char *)flags, size, compressed_buf, cmax, 3);
 
     if (nwrite > 0 && nwrite < size) {
 	if (write(fcb->null_fd, compressed_buf, nwrite) != nwrite)

vector/v.lrs/v.lrs.create/main.c

@@ -206,14 +206,14 @@ int main(int argc, char **argv)
     driver_opt->required = NO;
     driver_opt->description = _("Driver name for reference system table");
     driver_opt->options = db_list_drivers();
-    driver_opt->answer = db_get_default_driver_name();
+    driver_opt->answer = (char *) db_get_default_driver_name();
 
     database_opt = G_define_option();
     database_opt->key = "rsdatabase";
     database_opt->type = TYPE_STRING;
     database_opt->required = NO;
     database_opt->description = _("Database name for reference system table");
-    database_opt->answer = db_get_default_database_name();
+    database_opt->answer = (char *) db_get_default_database_name();
 
     table_opt = G_define_option();
     table_opt->key = "rstable";

vector/v.lrs/v.lrs.label/main.c

@@ -123,14 +123,14 @@ int main(int argc, char **argv)
     driver_opt->required = NO;
     driver_opt->description = _("Driver name for reference system table");
     driver_opt->options = db_list_drivers();
-    driver_opt->answer = db_get_default_driver_name();
+    driver_opt->answer = (char *) db_get_default_driver_name();
 
     database_opt = G_define_option();
     database_opt->key = "rsdatabase";
     database_opt->type = TYPE_STRING;
     database_opt->required = NO;
     database_opt->description = _("Database name for reference system table");
-    database_opt->answer = db_get_default_database_name();
+    database_opt->answer = (char *) db_get_default_database_name();
 
     table_opt = G_define_option();
     table_opt->key = "rstable";

vector/v.lrs/v.lrs.segment/main.c

@@ -93,14 +93,14 @@ int main(int argc, char **argv)
     driver_opt->required = NO;
     driver_opt->description = _("Driver name for reference system table");
     driver_opt->options = db_list_drivers();
-    driver_opt->answer = db_get_default_driver_name();
+    driver_opt->answer = (char *) db_get_default_driver_name();
 
     database_opt = G_define_option();
     database_opt->key = "rsdatabase";
     database_opt->type = TYPE_STRING;
     database_opt->required = NO;
     database_opt->description = _("Database name for reference system table");
-    database_opt->answer = db_get_default_database_name();
+    database_opt->answer = (char *) db_get_default_database_name();
 
     table_opt = G_define_option();
     table_opt->key = "rstable";

vector/v.lrs/v.lrs.where/main.c

@@ -85,14 +85,14 @@ int main(int argc, char **argv)
     driver_opt->required = NO;
     driver_opt->description = _("Driver name for reference system table");
     driver_opt->options = db_list_drivers();
-    driver_opt->answer = db_get_default_driver_name();
+    driver_opt->answer = (char *) db_get_default_driver_name();
 
     database_opt = G_define_option();
     database_opt->key = "rsdatabase";
     database_opt->type = TYPE_STRING;
     database_opt->required = NO;
     database_opt->description = _("Database name for reference system table");
-    database_opt->answer = db_get_default_database_name();
+    database_opt->answer = (char *) db_get_default_database_name();
 
     table_opt = G_define_option();
     table_opt->key = "rstable";