Profiler API

Realisation of Profiler agent.
Implemented:
Profiler.enable
Profiler.disable
Profiler.star
Profiler.stop
Profiler.getProfileHeaders
Profiler.getCPUProfile
Profiler.removeProfile
Profiler.clearProfiles
Profiler.addProfileHeader
Profiler.setRecordingProfile
Profiler.resetProfiles

Related: #185
Ideally, there should be an error message printed in the front-end console.