Corrected faulty invlet assignment in startup

There were some collisions between items in inv and items in worn. I
fixed this by prepopulating inv with every single item from character
creation, and then moving them to worn AFTER all the invlets had been
assigned by inv.
Merge PR #1826
Gettext support!

For starters, the main menu is now translatable.

More strings may be made translatable by including "translations.h",
then surrounding strings to translate with _().
For example: add_msg("my message") becomes add_msg(_("my message")).

Instructions for translating, and maintaining translation files,
can be found in TRANSLATING.md.
oops
replace magic numbers 80, 25 and related with FULL_SCREEN_WIDTH, FULL_SCREEN_HEIGHT
Merge PRs #1830 and #1832
Merged PRs together (no new ones).

Conflicts:
	newcharacter.cpp
Merge new character invlet assignment fix, magic number removal, and a start at gettext support.