Added special version of STRING-LEFT-TRIM for general vector bag and simple string.
Added special version of STRING-LEFT-TRIM for general vector bag and simple string.

clasp-developers/SICL,vtomole/SICL,clasp-developers/SICL,vtomole/SICL,clasp-developers/SICL,vtomole/SICL,vtomole/SICL,clasp-developers/SICL