added exception to run_task()

* added a try except for RaxmlError or PhymlError when analysing
subsets, these subsets will then be flagged as "unanalysable" so that
we can do something with them at the end of the run.
added unanalysable variable and fabricate_result() function

* the unanalysable variable will be set to true when something goes
wrong with the phylogeny program
* fabricate_result will do the same function as parse_model_result()
but will give the site log likelihoods added up from the last run as
the likelihood
added if statement to skip "unanalysable" subsets

* this will prevent from trying to analyse a "dummy_subset"
changed models to GTR+G and the search to kmeans
added dummy results to fabricate_result()
added RAxML and PhyML results to fabricate_result()

*PhyML and RAxML each have a different method processing results. Added
the essential items to each.
deleted print statements
fixed the Raxml and Phyml exception
deleted old exceptions

The old exceptions are now redundant given the new exceptions deeper in
the code (In run_task in the Analysis class in analysis.py).
status change unnecessary
cleaned up if unanalysable statement in KmeansAnalysis
Some comments for Paul
moved get_likelihood_list function to phyml and raxml

* get_likelihood_list had a section that did one thing for raxml and a
different for phyml. Split the function and put it in their respective
modules
* Also changed the kmeans_split_subset() to now call the function from
processor.
removed unanlysable command, raise PhylogenyProgramError

* PhylogenyProgramError is raised instead of PhymlError and RaxmlError
(duh!)
* moved unanalysable variable to fabricate_result() in subset.py
updated subset.unanlysable commands to subset.fabricated
added fabricate() for unanalyzable subsets
moved the fabricate function to processor

* also changed "unanalysable" variable to "fabricated". Now mark
subsets as "fabricated" if they use the fabricate_result() function
changed search and model
added site_lnls to subset before splitting subset
changed to take the site likelilhoods