Modified the shield system to become the dissipation system.
Implemented heat bar.
Purged shields and replaced with a dissipation bar that constantly lowers
and is raised by firing and using abilities.
When bar goes over limit, player cannot fire or use abilities until the
bar has decreased to 75%.
Abilities present in this branch have been modified to utilize heat.
Merged master to feature/heatbar
Merge pull request #19 from Covalent-Games/feature/heatbar

Feature/heatbar