Updated GUI and BLAST search

Gui updated (not tested). Changes: added default settings to custom primer entry form, converts entered sequence to caps, checks if any spaces are present in the DNA sequence and returns an error message if there is. 
Now extracts number of positive base matches and total alignment length from BLAST search and uses these to calculate the percentage of base matches in each hit. Use v high (100? 95?%) percentage hits to determine which pdb files are entered into the search.