Wrapper for evaluating code if feature can be loaded
Break out prologue/epilogue out of init

This allows having alternate ways of initializing Emacs in parallell with
loading the full configuration.
Support for using Emacs as a mergetool
Load basic configuration from prologue

The basic configuration is always needed so it should be loaded from the
prologue rather than duplicating it in every editor setup.
Put Emacs setups in setup subdir
Basic editor setup for fast startup
Mergetool cleanup
Emacs difftool support
Binding for VCS history