tessel/runtime#607 r=@tcr: Minor fixes for colonyinterpreter build.
tessel/runtime#604 r=@johnnyman727: match undocumented http.Agent inheritance, fixes #603
v0.1.20
Ignores .gdb_history.
Prevents uninitialized var in tm_random.
Adds UsageFault, MemManage, BusFault, and HardFault catches.