NuGet file: list all config files in all projects in the solution.
Ignore the entire NuGet packages dir, since package restore is enabled.

This is according to the comment in the .gitignore file:
# NuGet Packages Directory
## TODO: If you have NuGet Package Restore enabled, uncomment the next line
#packages/

No longer explicitly ignore specific installed packages.
Renamed CustomControls* to UserControls*

Renamed unchanged so that history tracking will work.
Logically renamed CustomControls* to UserControls* everywhere.

The rename was done because what's in those projects were user
controls.

"Custom controls" are extended from the library control classes.