Refactored fields to support any # of fields.

The field class is now a wrapper that contains a vector of any number of
fields at once. So now you can choke on smoke, burn in fire, and melt in
acid all at the same time. Fields now propagate additively... so if
something is spewing smoke instead of overwriting the old smoke, it adds
to its density.
Fixed some weird spreading behavior with smoke and fire.

Smoke now lasts longer and generates faster indoors, but small fires are
much less likely to destroy a building (density 1 fires). Fire will last
a more reasonable length of time.
Comments and monster field changes

If a field spawns ontop of you you will now be hit by it immediately.
Also commented things.
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
Converted player::wear_item to Allman style

For future commits.
Converted player::wear to Allman style

Just making it easier for me to modify.
Added non-interactive mode to player::wear

Now, we can use player::wear to "force" the player to wear stuff without
alerting him. Will be useful during character creation.
Made player::create armor equip more robust

Now, the player's profession might give him 10 pairs of pants, but he
can't wear them all at character creation.
Made advanced inventory sort items

Adresses issue #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.
Fixes NPC Morale Penalty
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 multi-field per tile support.

Conflicts:
	field.cpp
	game.cpp
	inventory.cpp
	mapdata.h
	npc.cpp
Merge new character invlet assignment fix, magic number removal, and a start at gettext support.
Added gettext -l flags for Windows builds.
Merge pull request #1834 from FunnyMan3595/win_load_gettext

Added gettext -l flags for Windows builds.