Added method for register click on buildings
Added upgrade cost to constants
Listen to click on screen method

When a touchEnd is registered, there will run method
that runs a methos in map.js. This is added because
the user should be able to click on buildings and
get information about them as well as the oppertunity
to upgrade them
Changed the code in map

Changed the code when a tap on a building
is registered
Added health view
Added health bar canvas
Added code for player health bar
Added player max hp constant
Player hp is now by default the PLAYER_MAX_HP constant
Money Hud now only listens for changes to the player's currency
Screen now only listens to the levels state changes, instead of all changes. As well as tiny code improvements
Removed a call to method

Removed the call to the showBUildingInformation
inside a if-sentence becuase when sliding over
the screen, the user touched the buildings.
Added upgrade logic

Added logic so the user can tap on a building and
get information. If the building is a powerplant,
the user can pay and upgrade.
Added level in defaults
Quick fix
merged master
Added text to the hp bar
Replace 'undefined' with 'null' in uninitialized variables

'undefined' is the value of an unknown variable, or rather the lack of a
value. 'null' is the lack of a value in a *known* variable.

See: http://stackoverflow.com/questions/801032/why-is-null-an-object-and-whats-the-difference-compared-to-undefined
Added a file for putting in global utility functions
Imported new code files