Add comments to blocking type number
Load mods in "default" game alongside other mods

This allows us to use mods that are part of the default game. In other
words, all games can use the same default mod provided by the engine,
instead of needing their own copy.
Add default game mod loading to mods->list()
Reverse directory order in mods->list()

We want the files in higher-priority directories to be placed at the end
of the vector, so they get loaded after (and thus over) the previous
files.
Fix mod_dirs ordering and remove duplicate code
FileParser: better error reporting
FileParser: clear error flags before reading a new file
EnemyGroupManager: remove ending / to have it working in Windows

Fixes 646.
Thanks @igorko and @RyanDansie for spotting and testing the bug.
Merge pull request #643 from stefanbeller/cleanup

Cleanup: Add some comments to MapCollider
Merge pull request #647 from stefanbeller/master

FileParser: Improve error reporting; Fix #646 in EnemyGroupManager
Merge pull request #644 from dorkster/default_game

Load mods in "default" game alongside other mods
Use WidgetScrollBox and WidgetLabel in MenuTalker

Closes #563
Fix MenuTalker's scrollbox stealing input

Also, WidgetScrollBox has been updated to support scrolling via keyboard
if the scrollbox doesn't contain any child widgets (i.e. plain text as
in MenuLog/MenuTalker).
Fix navigating WidgetScrollBox moving to next widget
Only allow one instance per Widget in a Tablist

Using this, we can easily add/remove Widgets as we toggle them in places
like MenuTalker. In MenuTalker, either the advance button or the close
button is show, so we don't want to allow selection of the disabled
button.
Fix quest index loading
Use WidgetScrollBox as caption buffer in GameStateCutscene

Closes #556
Merge pull request #652 from dorkster/bugfixes

Fix quest index loading
Merge remote-tracking branch 'upstream/master' into interface
Remove hard-coded scroll amount in WidgetScrollBox