Bind "f" and "b" keystrokes to next feature and previous feature, in …

…addition to "ctrl-f" and "ctrl-b". Also "shift-f" and "shift-b" to next/prev exon, in addition to "ctrl-shift-f/b". Fixes igvteam#1046

Taking scrolling into account when exporting images. Fixes igvteam#1033

Bug fix -- preference overrides from batch script were being stored p…

…ersistently

Changed to use sha512 for signing Windows installers

Fix broken paired end alignment popup text. Fixes igvteam#1003

Protect more calculated end positions from integer overflow. See issue …

…igvteam#977

Use full height of track to render features in "COLLAPSED" mode. Fixes …

…igvteam#990

remove unused code

fix module definition

Change preference hierarchy behavior -- user settings for generic ali…

…gnment tracks ("Alignments" tab) will now cascade down to RNA and 3rd gen alignments if there is no specific user setting for those types. Fixes igvteam#760.

code cleanup