little adjustments to Namespace.java
Added some exception to discriminate what kind of error has to be
returned when the StoRI computation fails
Explanation string is truncated if too long
Fixed sym link management
Fixed StoRI resolving
Fixed Namespace StoRI resolution alghoritm
Fixed typo
Fixed SRM_INVALID_PATH returned if surl is unsolvable
Merged with branch 'develop'

Conflicts:
	src/main/java/it/grid/storm/space/SpaceHelper.java
Merge pull request #17 from italiangrid/fix/STOR-307

Fix/stor 307