Vector convenience method additions

Squashed commit of the following:

commit 04b2e473e826670538ba86097051beaea802dc82
Author: Caskman <eric.cascketta@gmail.com>
Date:   Thu May 2 22:47:07 2013 -0700

    added convenience methods for vector
Better collision behavior; impulse input added as well

Squashed commit of the following:

commit 44a7b18aa739fb70b3500410fd117e486b0e6b84
Author: Caskman <eric.cascketta@gmail.com>
Date:   Sat May 4 08:53:36 2013 -0700

    added left mouse and spacebar impulse functionality

commit cf906319d9a4fefa07ca3a7f7528136249205241
Author: Caskman <eric.cascketta@gmail.com>
Date:   Sat May 4 08:36:18 2013 -0700

    moved view bounds checking to before collision checking, reduced penetration even more

commit e14f8590a4fc4c0c1189c1d0c3d5e967223cb83e
Author: Caskman <eric.cascketta@gmail.com>
Date:   Sat May 4 08:26:46 2013 -0700

    Moved adding gravity to before collision checking, reducing penetration

commit e2ebb3bc23ca95264309ffe9ff57f2f7f38ab816
Author: Caskman <eric.cascketta@gmail.com>
Date:   Fri May 3 11:56:40 2013 -0700

    checkpoint

commit afefc3aa981ce75861860e2ec437482ea06e6a97
Author: Caskman <eric.cascketta@gmail.com>
Date:   Fri May 3 10:54:30 2013 -0700

    migrated code to absolute view space

commit 0453e6296ab29dcf330bbf4fd6a3c7d70fd1569f
Author: Caskman <eric.cascketta@gmail.com>
Date:   Fri May 3 10:39:36 2013 -0700

    changed bound checking from unit space to view space; will migrate rest of code from unit space to view space

commit cf571da3f6d46c8f1314186daf9d948bccac0055
Author: Caskman <eric.cascketta@gmail.com>
Date:   Thu May 2 22:41:55 2013 -0700

    checkpoint

commit 32713d68fddb90ac0233a57b886a544dffc94e0e
Author: Caskman <eric.cascketta@gmail.com>
Date:   Thu May 2 19:41:39 2013 -0700

    collisions are detected, resolveCollisions is being called, but visibly nothing is happening

commit 534c89642defd46119553da5ba9cb3cc93d1d247
Author: Caskman <eric.cascketta@gmail.com>
Date:   Thu May 2 19:15:14 2013 -0700

    checkpoint

commit 09a1c1abad58c053c51193b9ba841a9898b5f409
Author: Caskman <eric.cascketta@gmail.com>
Date:   Thu May 2 18:50:14 2013 -0700

    checkpoint
Magically beautiful physics

Conflicts:
	src/cask/physics/model/GameModel.java
	src/cask/physics/model/entities/Particle.java