CHANGELOG_CURRENT

Clone assembler now separates clones with different V/J/C genes
Added new action `alignmentsDiff`: run as `mixcr alignmentsDiff file1.vdjca file2.vdjca report.txt` to find difference between to .vdjca files
Added support for P-segments; new gene features `VPSegment`, `DLeftPSegment`, `DRightPSegment`, `JPSegment` are now available both in `exportAlignments` and `exportClones`
Fixed wrong boundaries of FR3 and CDR3 in Mouse TRA/TRD references imported from IMGT
minor: Added new export field: -vBestIdentityPercent and -vIdentityPercents (-j..., -c... in the same way)
minor: now IMGT import script produces more useful information