phabricator: add addremoved and addmodified functions These are relatively simple so add them together. As the name indicates, these add phabchange objects for removed and modified files to the phabdiff. Differential Revision: https://phab.mercurial-scm.org/D7049

phabricator: add makebinary and addoldbinary functions These populate the phabchange with the data for a binary file, much as maketext does for text files. Differential Revision: https://phab.mercurial-scm.org/D7048

phabricator: add the uploadfile function This is needed to be able to submit binary files such as images in commits (and also non-UTF-8 text files). One of the primary disadvantages of the current use of createrawdiff is that Phabricator simply drops any binary diffs included in the patch, but not the files, so if such a diff is then committed it corrupts any binary files in it. Differential Revision: https://phab.mercurial-scm.org/D7047

phabricator: add the uploadchunks function Differential Revision: https://phab.mercurial-scm.org/D7046

phabricator: add the maketext function This add the diff data for a text file to a phabchange. Differential Revision: https://phab.mercurial-scm.org/D7045

phabricator: add the phabdiff data structure This holds all the data about a commit, and is passed to the differential.creatediff API. Differential Revision: https://phab.mercurial-scm.org/D7044