New project.cfg format v.2

After several months of using scmproj in real work I found current project.cfg v.1 is not ideal. Therefore I should change it.

1) I should get rid of ALTs concept. At all. It seems it bad for describing different components layouts and has limited use only for feature or maintenance branches. Also ALTs are blockers for correct implementation of snapshots (specifically for merging snapshots).

2) Change policy of using only UPPERCASE_AND_UNDERSCORES for settings names in config. lowercase-and-dashes are simpler to use in the pcmd.

3) We still will support old format (v1) for backward compatibility reasons, but with new format do some things a bit differently.