[#221] ydbinstall.sh uses gtm* environment variables

The ydbinstall.sh script uses environment variables to control certain advanced
functionality of the script. These were previously gtm prefixed variables,
but for consistency purposes they should be ydb prefixed variables.

Modify the ydbinstall.sh script to look for ydb prefixed variables
and set the corresponding internal variable to the value of the ydb
prefixed variable, while mantaining backwards compatibility with gtm
prefixed variables.

sr_unix/ydbinstall.sh

@@ -158,6 +158,18 @@ mktmpdir()
 }
 
 # Defaults that can be over-ridden by command line options to follow
+# YottaDB prefixed versions:
+if [ -n "$ydb_buildtype" ] ; then gtm_buildtype="$ydb_buildtype" ; fi
+if [ -n "$ydb_keep_obj" ] ; then gtm_keep_obj="$ydb_keep_obj" ; fi
+if [ -n "$ydb_dryrun" ] ; then gtm_dryrun="$ydb_dryrun" ; fi
+if [ -n "$ydb_group_restriction" ] ; then gtm_group_restriction="$ydb_group_restriction" ; fi
+if [ -n "$ydb_gtm" ] ; then gtm_gtm="$ydb_gtm" ; fi
+if [ -n "$ydb_lcase_utils" ] ; then gtm_lcase_utils="$ydb_lcase_utils" ; fi
+if [ -n "$ydb_overwrite_existing" ] ; then gtm_overwrite_existing="$ydb_overwrite_existing" ; fi
+if [ -n "$ydb_prompt_for_group" ] ; then gtm_prompt_for_group="$ydb_prompt_for_group" ; fi
+if [ -n "$ydb_verbose" ] ; then gtm_verbose="$ydb_verbose" ; fi
+if [ -z "$ydb_change_removeipc" ] ; then ydb_change_removeipc="yes" ; fi
+# GTM prefixed versions (for backwards compatibility)
 if [ -z "$gtm_buildtype" ] ; then gtm_buildtype="pro" ; fi
 if [ -z "$gtm_keep_obj" ] ; then gtm_keep_obj="N" ; fi
 if [ -z "$gtm_dryrun" ] ; then gtm_dryrun="N" ; fi
@@ -167,7 +179,7 @@ if [ -z "$gtm_lcase_utils" ] ; then gtm_lcase_utils="Y" ; fi
 if [ -z "$gtm_overwrite_existing" ] ; then gtm_overwrite_existing="N" ; fi
 if [ -z "$gtm_prompt_for_group" ] ; then gtm_prompt_for_group="N" ; fi
 if [ -z "$gtm_verbose" ] ; then gtm_verbose="N" ; fi
-if [ -z "$ydb_change_removeipc" ] ; then ydb_change_removeipc="yes" ; fi
+
 
 # Initializing internal flags
 gtm_group_already="N"