incremental releases

[varhub]

Related to #268

Test roadmap

Minimal Test:

1. Simple cmake .. to ensure it is working
2. Check .deb generated by metapackages
3. make package and check it

A. Real case usage I:

1. cmake or make package and push .deb to repo
2. repeat x2 and see incremental rc

B. Real case usage II:

1. Change major/minor/patch
2. cmake and check suffix == -rc1

C. Test script bounds I:

1. do by hand a x.y.z-rc9 and rc10
2. push both into repo
3. cmake to see if versioning number is respected
   • wrong result: -rc10
   • success result: -rc11

D. Test script bounds II:

1. Change manually CPACK_DEBIAN_PACKAGE_VERSION
2. See what happens. Expected:
   • warning but ok
   • version is unchanged

[fqez]

Tested and working! Thanks!