Bugfix: Use the SW_HOSTNAME being passed to _sw_profiles_init
Refactor: Don't setup EDITOR until after all plugins have run

This allows us to remove a 'source' line.
Refactor: Move _sw_load into the loader plugin file
fixup! 07e326a513af726d4560a8880a1d90f648be437d
Refactor: Source plugins directly since we don't want them cached
Bugfix: Available editor array was incorrectly parsed

It was one big string of editors instead of 4 individual values
Feature: Add the lib for caching
Refactor: Replace instances of 'source' with 'cache_or_source'
Feature: Enable loader caching
fixup! 0035160f694c9b3902876672bdf76600bd24989e
Bugfix: Remove meta-plugin children from default list

The removed plugins are added by meta-plugins such as 'editor',
'package-manager', etc.
Bugfix: Fix package-manager to add plugins in the new way
fixup! ebb087d
Feature: Rename issue_tracker plugin to issue-tracker

For consistency
Refactor: Change before_loader hooks to meta hooks

There's a big difference between a hook which just determines which
other plugins need to be installed (a metaplugin such as editor,
ruby-version-manager, etc) and a true 'before_loader' hook.

This commit distinguishes between the two.  The added bonus of doing 
this is that we can now choose not to cache any of the meta hook files.
fixup! 7e98c80e88357747355d74b89305a53f3b8b71a8
Refactor: Don't cache sourced files inside of meta hooks

They're only there to tell the loader what other plugins to load.

Because those plugins will do the caching themselves, there's no need
to cache these.
Refactor: Move the profiles init to the lib directory

This was getting loaded twice into the cache due to the fact that it
was considered a 'plugin'.

Once in `lib/profiles.sh` and once more on `_sw_load_extension 'plugin'`
Refactor: Remove unneeded sourcing of the VCS plugin file

This was causing the VCS plugin file to be loaded 3 times.
Refactor: Remove the sourcing of the rails plugin in the rake

This was causing the Rails plugin to be cached twice.