build: changed .gitattributes so project settings files will no longer cause merge conflicts.

   Specific setting files added to .gitignore so local changes will not be included in the commit by default
   Changes from the repo will not overwrite the local copy because "ours" merging strategy is specified

To commit any changes into these files you have to use 'git add -f filename'
Depending on your git version you may need to enable the 'ours' merge driver for the project:

$ git config merge.ours.driver true

To avoid adding back your local config file changes to the repo, execute the
_scripts/track-config-files-off command. This will prevent git to check for file changes.
Use _scripts/track-config-files-on to enable hange tracking.