Make Updater project external

See:
https://github.com/imagej/imagej-updater
Migrate core options to imagej-common component

See:
https://github.com/imagej/imagej-common/commit/16f7d05729a8269c33c2383691933454296bf37d
Migrate TunePlayer to SciJava Common

See:
https://github.com/scijava/scijava-common/commit/2a40b7718d998b873cd2c08837c3271cac9d4091
Migrate core commands to external repositories

See:
* https://github.com/imagej/imagej-plugins-commands
* https://github.com/scijava/scijava-plugins-commands