Fix #94 and Android DPI

- The accelerometer does not cause an instant unstitch on android anymore. This was caused by different calculation of gravitation in iOS and Android, which has now be unified
- Since we are unable to get the actual DPI on android devices, we now assume a DPI of 142, which is pretty accurate for most android devices
- Introduced a remotelog feature: Sending a remotelog message to a device causes a CWDebug.log() on them. This can for example be used to log stuff on the master (and therefore in Xcode)