Fix Issue 5753 - Disallow map with void function.

https://d.puremagic.com/issues/show_bug.cgi?id=5753
Add uniform example for enums.
Merge pull request #1932 from AndrejMitrovic/UniformDocs

Add uniform example for enums.
Merge pull request #1917 from Poita/bug5753

Fix Issue 5753 - Disallow map with void function.