Fix solution/project files for nested directories.

By having the leading `/` infront of the `*` makes these types of files relative to the directory the gitignore is in. If you create a Unity project inside of a git directory Unity forces you to create a new directory, thus not picking up these files.
Merge pull request #1307 from Frozenfire92/patch-1

Unity: Fix solution/project files for nested directories.
no good reason to ignore sql folder
Merge pull request #1315 from bbodenmiller/patch-4

VisualStudio.gitignore: no good reason to ignore sql folder
Add space at Unity gitignore comment
Merge pull request #1317 from arkeidolon/patch-1

Add space at Unity gitignore comment