Added new function 'getProteinInfoFromTheInternet' to check Uniprot or Entrez based on ACs

The function 'getProteinInfoFromTheInternet' checks whether the AC has
the pattern of Uniprot or Entrez Protein ACs, and submits those them
to the respective database.

Further, the ProteinGroup initializer now writes a 'database' to the
isoform_to_geneproduct table. Splice variants are only determined for
those ACs which do have the Uniprot pattern.
use utility functions to determine which ggplot function to use
Cleanup of isobar-analysis.Rnw

- use of ltxtables to allow optimal column widths (longer runtime,
however)
- use [[ instead of $  for accession of lists
- better column and grouping description
bugfix: use grepl instead of grep
update to version 1.9.3