Moves allocateStackObject from JITRuntime to MethodCompiler

Issue #11
MethodCompiler::createArray now uses stack allocation.

Issue #11
Prettifies the usage of memset function inside LLVM IR.

Issue #11
Reverts List methods. Removes fields tail and head.

Issue #18
Merge remote-tracking branches 'origin/feature/11/jit_stack_allocation' and 'origin/bug/18/list_tail' into develop

* origin/feature/11/jit_stack_allocation:
  Prettifies the usage of memset function inside LLVM IR.
  MethodCompiler::createArray now uses stack allocation.
  Moves allocateStackObject from JITRuntime to MethodCompiler

* origin/bug/18/list_tail:
  Reverts List methods. Removes fields tail and head.