Refactorize migration tool
Refactorize migration tool

This refactoring run deals with:
* unintuitive naming,
* late input validation,
* passing only parts of input during option parsing,
* unconsistent comments.

Additionally, this patch:
* adds possiblity to install database in a custom directory,
* removes possibility of removing whole Cynara's state directory during
  deinstallation - now only database is removed by migration tool.

Change-Id: I59e429d93812861ca9c32f201ed0056f753cbc25

pohly/cynara,Samsung/cynara,Samsung/cynara,pohly/cynara,pohly/cynara,Samsung/cynara