Update - a backlog of fixes

A fairly large dump of old upgrades, fixing crashes, adjusting Steam integration, adding translation hooks, and all sorts of other minor things. If you encounter any crashes or problems with the new version, please let us know!

Full changelog follows:

* 'numbered_combantants is not defined' crash in turnbasedcombat.rpy fixed.
* Disambiguation tags added.
* 'Next: %d' string (XP needed for next level on profiles page) now
translatable.
* . added to Espresso tooltip.
* Decrufting.
* AttackStr() changed to AttacksStrLocalized(), so it's more clear that it
should handle any grammatical rules.
* Grex AttackStrLocalized() now learns about the attacks to show in a
translatable fashion.
* Risk Analysis now translates the monster type.
* Risk Analysis translation string clearer.
* No longer try to translate (player-entered) leader's name.
* Difficulty level on profile screen now translated.
* Insufficient-SP failure on Risk Analysis no longer hides all the combatants.
* Translation code should now load all .strings files in translations/$lang/
* ADVCharacter_ignore_say_attributes now compatible with 6.99.12.2.
* scalablenarrator works in 6.99.12.2.
* Some string deduping.
* Load screen works in 6.99.12.2.
* More string deduping.
* Title screen hotspots translatable.
* Refactoring: moved newtranslation.rpy stuff into translation.rpy.
+ String extraction.
* Credit screen copyright bumped to 2009-2017 (was 2009-2016)
* Cheeve code tweaked to interface with Steam using the newstyle (64-bit
friendly) version.
* Credits year bumped to 2019.
+ Steam integration completely reworked
* include python_dict and python_set declarations in unroller.py for new
cheeves.
+ No longer include symlinks in Steam integration
+ Removed unlock_cg from steamsh.
+ Makefile to update steamsh distributables.
* all_checklist_items_ordered now correctly initialized.
* Now use steam-overridable checklist_item_is_unlocked() func to determine
what cheeves to show locally.