Move setup files into subdirectories. Move mode directories to modes subdir.
This will make it easy to specify a recipe in melpa that maintains the directory
structure. Add interactive functions to jump to .el and README files

See #170

With autoload, it doesn't need "require" the package before call
evil-collection-*-setup function.

Remove declare-function workaround.

Adding for byte compiling.

TODO: Should look into doing an import instead since we shouldn't need
to declare a function that our library should know about.

I think there was some circular dependency around evil-collection-*
requiring evil-collection.el so I went with the quick and dirty
approach of doing a declare-function. If someone has a better idea,
feel free to change this!

Also add evil-collection-setup-hook. Fixes #5 and #98.