Shooting projectiles in space

* Projectiles are shot by hitting "f".
* Projectiles have certain life span (path length) and movement
speed.
* Does not affect other ships yet.
* Add test for projectile class.

Commit references #2.
Major refactoring for TDD: modules

* Rename player and ship types to interior and exterior respectfully.
* All non-UI related modules have unit tests (small exceptions will be
dealt with).
* Game is more object driven.
Complete major TDD refactoring
Minor: python code PEP8 compliance
Minor bugfix: "say" behaviour returned to normal
Spaceships can be blown up now

* However, need separate spaceships/players for feature to work.

Commit references #2.
Interiors are assigned to spaceships now

* All spaceships have their own interior.
* Player has to set desired spaceship name via config.ini.

Commit references #8.
Spaceship is piloted by activating console

* To enter flight mode - activate navigation console. To exit - press
"F" key. Ship will continue moving when you exit.

Commit closes #8.
Spaceships can not be piloted after crash

* Need more graceful death in the future, though.

Commit closes #2.
Merge branches 'dogfights' and 'refactor' into develop