Refactor Charon database syncing and CharonSession object methods

Yeah I noticed an incongruency there but I think we're catching the same thing. I see though that I didn't update the example in the comment. My expectation is a file that looks like this:

`A.Wedell_13_03_P567_102_A_140528_D00415_0049_BC423WACXX`

Is that correct? If so, then here we'd have:

 - `project_name`:	`A.Wedell_13_03`
 - `sample_id`:	`P567_102`
 - `libprep_id`:	`A`
 - `seqrun_id`:	`140528_D00415_0049_BC423WACXX`