Merge pull request #1926 from gaelicWizard/basenamed

Use parameter substitution instead of `dirname`/`basename`, where safe to do so

install.sh

@@ -184,7 +184,7 @@ if [[ -n "${no_modify_config}" && -n "${append_to_config}" ]]; then
 	exit 1
 fi
 
-BASH_IT="$(cd "$(dirname "$0")" && pwd)"
+BASH_IT="$(cd "${BASH_SOURCE%/*}" && pwd)"
 
 case $OSTYPE in
 	darwin*)