Allow access to structured object representation of patch data

[bittrance]

This PR does two things: 1) gives control over the context size of patches, and 2) adds a method that allows retrieving a patch in the shape of an object with a list of hunks. E.g.:

diff.structuredPatch('oldfile','newfile','line2\nline3\nline4\n','line2\nline3\nline5','header1','header2'){oldFileName: 'oldfile',newFileName: 'newfile',oldHeader: 'header1',newHeader: 'header2',hunks: [{oldStart: 1,oldLines: 3,newStart: 1,newLines: 3,lines: [' line2',' line3','-line4','+line5','\\ No newline at end of file'],}]}

If it looks acceptable, I'll patch documentation et cetera.

[kpdecker]

This formatting was intentional. Style is to chain vars with , and to double indent when newlines are used to line up the var names.

[kpdecker]

This generally looks good outside of a few style concerns and a few cases where I'm not sure what the exact behavior is. Once we get those fixed up, I'm glad to merge.

[bittrance]

Whitespace adjustments done.
Hunklines var removed in favour of curRange.

[bittrance]

Documentation added.

[kpdecker]

Thanks!

[kpdecker]

Released in 2.0.0