Add Config::getSources

The settings-view needs this so that it can display snippets
associated with packages
Tweak log prefix text
Fix logic error when exception is thrown in config observer
In PackageManager::activatePackage reject, don't throw
Simply deprecation output
Fix grammar in spec description
:lipstick: package-manager-spec
Merge pull request #4755 from atom/mb-fix-disabled-package-situation

Fix recurring errors when a non-existent package is disabled
Speed up and simplify config file reloading
Merge pull request #4753 from atom/mb-add-config-get-sources

Add Config::getSources
:arrow_up: tree-view@0.141
:arrow_up: bundled packages w/ new c++ scope name

* language-ruby@0.46.0
* language-objective-c@0.14.0
* language-gfm@0.57.0
* language-c0.35.0
* symbols-view@0.73.0
Merge pull request #4756 from atom/mb-speed-up-config-loading

Speed up and simplify config file reloading
:lipstick: Organize config-spec

* Group tests by method rather than by scoped vs unscoped
* Group deprecated methods together
* Group internal methods together
* Make descriptions more consistent