Correct whitespace inconsistencies

There are a number whitespace differences throughout the framework codebase. This should clean them all up.

- Windows line endings have been replaced with unix line endings (```grep -lIrH "^M" . | xargs dos2unix```)
- Tabs have been expanded to 4 spaces. I couldn't find any information about what Laravel uses, but since both PSR-0 and PSR-1 are followed I assumed that PSR-2 would also be followed which says "Code MUST use 4 spaces for indenting, not tabs" (```find .  -type f -not -path "*.git*" -exec bash -c 'expand -t 4 "$1" > /tmp/expand && mv /tmp/expand "$1"' _ {} \;```)
 - Files have a new line added to the end of them (```find . -type f -not -path "*.git*" -exec sed -i '' -e '$a\' {} \;```)
 - Trailing whitespace has been removed (```perl -pi -e 's/ +$//' **/*```)

There should be no code changes in this commit, it is all purely cosmetic. Running ```git diff --ignore-space-change master...correct-whitespace``` locally for myself returns an empty diff.

If there is anything wrong/missing with this just let me know and I can update the patch.