malformed resource pack can cause client crashes

Game crashed when selecting a resource pack (that I was trying to get working, but was not formatted correctly)

*What I expected to happen was... that the game wouldn't crash?

What actually happened was...:
It crashed.

Steps to Reproduce:
1. Put a malformed resource pack in the resources folder
2. Maybe the game will crash when you activate it (it didn't crash every time)

What's needed (probably):

Errors from reading malformed resource packs should be caught and logged - it would be nice if the logs or error message would let the user know something about what went wrong (I knew because I was actively working on making my first resource pack – but a standard user downloading and installing my pack might not realize that my malformed pack was causing the issue.)