Update README.md

added boost dependency
Update README.md
Merge pull request #296 from TheAncientGoat/master

Add new dependencies to build instructions
UI and event refactoring; add music support; fix torture table apply crash, vec2 out of bounds crash;
missing files
Merge branch 'master' of https://github.com/miki151/keeperrl
fix compile error
add barricade; display some additional minion info in minion view; revive ambush skill; add elven vision; fix scrollable rendering; change elven village;
add jukebox
makefile fix
makefile fix
fix some initialization crashes
fix color issues
add lighting and torches; add consumable limit for minions;
add buff timeouts to UI
damage/accuracy variance change; keeper more powerful
fix square factory mem leak
add bridge; move torch and barricade to workshop, imp to library;
add pathfinding sectors
allow creatures to get stuck when impassable square is built