increase MAX_REQNUM_SIZE consistent with change to request_number col SIGNED -> UNSIGNED

trapped dbi errors in try/catch block, so handled same as other VEP.pm errors; replaced NGS::MooX::Types with Local::MooX::Types; changed existing_variation col in vep_data & sample_data tables to TEXT due to entry >255 chars

added ability to set max x & y-axis values in chartdirector output; 02-vcf-analysis script loads ngs.locations db table for use in start position exclusions

new vcf analysis section; moved ChartMaker to NGS::ChartMaker