Be more dash friendly.

Change-Id: Ie0e67456e2580a1428aa36632788d6213c340d0c
Reviewed-on: http://gerrit.dmdirc.com/956
Automatic-Compile: DMDirc Local Commits <dmdirc@googlemail.com>
Reviewed-by: Gregory Holmes <greg@dmdirc.com>

installer/linux/getjre.sh

@@ -32,7 +32,8 @@ if [ "${BASEDIR}" = "${0}" ]; then
 	BASEDIR=`which $0`
 	BASEDIR=${BASEDIR%/*}
 fi
-if [ "${BASEDIR:0:1}" != "/" ]; then
+CHECKBASEDIR=`echo "${BASEDIR}" | sed 's#^/##'`
+if [ "${CHECKBASEDIR}" = "${BASEDIR}" ]; then
 	BASEDIR=${PWD}/${BASEDIR}
 fi;
 

installer/linux/installjre.sh

@@ -47,7 +47,8 @@ if [ "${BASEDIR}" = "${0}" ]; then
 	BASEDIR=`which $0`
 	BASEDIR=${BASEDIR%/*}
 fi
-if [ "${BASEDIR:0:1}" != "/" ]; then
+CHECKBASEDIR=`echo "${BASEDIR}" | sed 's#^/##'`
+if [ "${CHECKBASEDIR}" = "${BASEDIR}" ]; then
 	BASEDIR=${PWD}/${BASEDIR}
 fi;
 

installer/linux/setup.sh

@@ -52,7 +52,8 @@ if [ "${BASEDIR}" = "${0}" ]; then
 	BASEDIR=`which $0`
 	BASEDIR=${BASEDIR%/*}
 fi
-if [ "${BASEDIR:0:1}" != "/" ]; then
+CHECKBASEDIR=`echo "${BASEDIR}" | sed 's#^/##'`
+if [ "${CHECKBASEDIR}" = "${BASEDIR}" ]; then
 	BASEDIR=${PWD}/${BASEDIR}
 fi;
 

installer/linux/uninstall.sh

@@ -29,7 +29,8 @@ if [ "${BASEDIR}" = "${0}" ]; then
 	BASEDIR=`which $0`
 	BASEDIR=${BASEDIR%/*}
 fi
-if [ "${BASEDIR:0:1}" != "/" ]; then
+CHECKBASEDIR=`echo "${BASEDIR}" | sed 's#^/##'`
+if [ "${CHECKBASEDIR}" = "${BASEDIR}" ]; then
 	BASEDIR=${PWD}/${BASEDIR}
 fi;
 

launcher/unix/DMDirc.sh

@@ -57,7 +57,8 @@ if [ "${BASEDIR}" = "${0}" ]; then
 	BASEDIR=`which $0`
 	BASEDIR=${BASEDIR%/*}
 fi
-if [ "${BASEDIR:0:1}" != "/" ]; then
+CHECKBASEDIR=`echo "${BASEDIR}" | sed 's#^/##'`
+if [ "${CHECKBASEDIR}" = "${BASEDIR}" ]; then
 	BASEDIR=${PWD}/${BASEDIR}
 fi;