Pluggable solver framework for pkgng. Weeks 1-2.

[Vsevolod Stakhov]

Hello,

I'd like to report that the following tasks were done over the previous 
2 weeks:

- created and tested conflicts detection algorithm for package 
repository generation;
- added support for explicit conflicts in manifest emitting/parsing;
- added utility functions to operate with packages conflicts.

My code is placed here: https://github.com/vstakhov/pkg/tree/gsoc

However, conflicts writing to main sqlite database is not still 
implemented, and I plan to finish this task by the end of this week.

As the next step I want to implement logic of provides and requires for 
packages.

-- 
Vsevolod Stakhov