README update
GllogPatchPr and GllogPatchDiffPr  commands
Do not run `:Gblame` when OpenFromDiff()

sometimes we need :Gblame, sometimes not. Let the user decide.
renamed all functions to *Tab
extract flayouts#tabvsplit()
parameterize LogPatch() with file name
OpenFromDiff is not depending on vertical split existance

It leaves only diff window and makes a split with file from chunk by
itself
Drop ability to run GllogPatchTab & GllogPatchPrTab from diff

Too much pre-defined logic. Better let user to combine these commands
himself.
Pull Request commits should be in reversed mode

The same way as they shown on Github
Rename pull request commits functions
OpenFromDiff: when switching back to diff, return to the same line
Fix OpenFromDiff post-selection position

When we called OpenFromDiff() on a chunk, and this file have multple
changed chunks, the post-selection position was pointing always to the
first chunk.
PullRequest renamed to PullRequestSummary
Parameterize PullRequestCommits with base branch name
..: indent
Documentation update