Add scripts to use the LogcatTiming easier

[radekdoulik]

Using the LogcatTiming targets is too verbose

msbuild /v:d build-tools/timing/timing.csproj /t:LogcatTiming /p:PID=...

The script might check the adb output to find PID of the last monodroid-timing message and run the target with this PID.

It might also filter the msbuild output to show only the lines with timing information.

We will probably need 2 scripts. For Windows an Mac.