RelationshipResolver now checks sanity before installing.

This was a surprisingly easy change, and it results in a really cool
list telling the user why what they've asked for isn't possible.

This also gives the Registry some nicer interfaces, eliminates duplicate
lines in our sanity checkout output, and expands the things the
InconsistentKraken can work with.

Fixes #332.
Missing modules are now info, not warning level.

This isn't something the end user can really do anything about, so we
shouldn't be warning them.
RelationshipResolver no longer suggests conflicting mods

If something would conflict with a mod we already have installed, or are
about to install, we remove it from consideration. While the previous
commit in this sequence ensures we never try to install conflicting
mods, this change ensures we provide a *shorter list* of
inconsistencies, so the user isn't scratching their head quite so much
wondering why a whole slew of things were going to be installed when
they conflict.

Fixes #332.
Merge branch 'release-v1.0' into 332_mod_conflicts

* release-v1.0: (23 commits)
  Fixes for review comments on #313.
  CmdLine: No longer spam the user with file removes
  Force a GameData scan after installing mods.
  NetAsyncDownloader: Throw MissingCertificateKraken on missing certs.
  Cmdline: Fix typo: "Manage KSP insatlls".
  No longer query the user during transactions.
  Disable experimental features iff we're on a stable branch.
  cmdline: Better messages when upgrading not-installed mods.
  `ckan remove`: better message if the mod wasn't there to start with.
  ModuleInstaller.UninstallList now throws a ModNotInstalledKraken
  Fixup ModuleInstaller to use preferred path functions.
  InstalledModule has regions, tidyup, fewer warnings.
  Automatically detect older registry versions and upgrade.
  Registry.DeregisterModule now works with new relative/absolute paths.
  RegisterDll now works properly using relative paths.
  Registry now always stores files in relative format.
  Added `ToRelative` and `ToAbsolute` to KSP.
  Commented on some things we should do in the registry.
  Added KSPPathUtils.ToAbsolute
  Added KSPPathUtils.ToRelative
  ...
Fixup for changed properties on InstalledModules.

InstalledModule.source_module -> Module
Allow release candidates in tag tests. :)
Merge pull request #338 from KSP-CKAN/332_mod_conflicts

RelationshipResolver fixes