introduce convenience class for HTTP client connections. closes #128
introduce EventBus concept.

this was required as for defining OBDII adapter specific protocol
handling and to de-couple certain components and their logic.
outsource location update listener; remove AndroidUtil; bluetooth stuff
add measurementcandidate and collector.
extract command requests to protocol classes.
rename some interfaces and components to better match their semantics
refactor backgroundservice classes
refactor some BackgroundService related classes.
set git commit hash as android:versionName in bin/AndroidManifest.xml.
closes #133
reflect BackgroundService refactor in AndroidManifest.xml
minor changes in consumption calculation and maf calculation
minor changes in consumption calculation and maf calculation
add simple obd simulator app
modify .gitignore
remove autoconnect thread. outsourced to a backgroundService.
disable AndroidHandler as java.util.logging seems to be forwarded
anyways.
define method invariants
add backgroundService for automatic device discovery.
Merge branch 'refactor-outsource-matthes' of https://github.com/matthesrieke/enviroCar-app into develop
modify gitignore