Version parsers

[cmdcolin]

The majority of bigwig/bigbed file format spec include the supplementary info which is https://www.ncbi.nlm.nih.gov/pubmed/20639541 and existing parser implementations

The supplementary info doc describes version 3 of the file format

The stats field only exists in 3 and not 2, but I have not seen any version 2 files that have caused this issue

The current bigwig version that seems widespread is now version 4, and I am not sure what changes were made in this version

[rbuels]

Hate to say it, but the best source for current info is probably going to be reading the source code. See https://github.com/ucscGenomeBrowser/kent/blob/master/src/lib/bbiRead.c#L80

[rbuels]

Here's a comment with a concise version history:

https://github.com/ucscGenomeBrowser/kent/blob/master/src/inc/bbiFile.h#L75

[rbuels]

Here's the bigwig creation main func: https://github.com/ucscGenomeBrowser/kent/blob/master/src/lib/bwgCreate.c#L980