Introduce end-of-line normalization on OS specific files

The main issue is with some DOS Batch files which contains a mix of LF and CRLF end of line characters.
=> Ensure CRLF on DOS Batch files
In the mean time, ensure LF eol on Unix Shell files with a .gitattributes file (see http://git-scm.com/docs/gitattributes/).

Update CORG/Installing+Git documentation with recommended Git configuration.