ui: document the formatted(), interactive() & plain() functions.

ui: add ui.formatted configuration variable and accessor function. This new configuration variable is similar in nature `ui.interactive', but applying to output instead of input. This allows as to support non-interactive sessions where formatted should be enabled, such as when using the pager extension. The variable itself is left undocumented; it is not intended for use outside Mercurial and its extensions.

revlog: fix inconsistent comment formatting

improve --branch processing (and differentiate from # syntax) Previously #foo and --branch foo were handled identically. The behavior of #foo hasn't changed, but --branch now works like this: 1) If branchmap is not supported on the remote, the operation fails. 2) If branch is '.', substitute with branch of the working dir parent. 3) If branch exists remotely, its heads are expanded. 4) Otherwise, the operation fails. Tests have been added for the new cases.

help: show value requirement and multiple occurrence of options this helps users to know what kind of option is: - no value is required(flag option) - value is required - value is required, and multiple occurrences are allowed each kinds are shown as below: -f --force force push -e --ssh CMD specify ssh command to use -b --branch BRANCH [+] a specific branch you would like to push if one or more 3rd type options are shown, explanation for '[+]' mark is also shown as footnote.

keyword: pass context to kwtemplater.overwrite Now that we have retrieved the context in every calling function except commit, pass it as argument to kwtemplater.overwrite to avoid looking it up twice. Reorder arguments to kwtemplater.overwrite to reflect their importance. Turn node argument into a simple boolean and rename it to iswctx.

parser: fix missing param in _match

commit: add tests for the 'created new head' message

commit: fix display of 'created new head' message (issue2186) To avoid recurrent fixes for the display of this message, a summary table with all case combinations has been added to the code. Basically, there is two condition for the message to be printed: * this is not an initial (named branch or topo) root * none of the parents are in the current branch heads

rebase: --abort doesn't strip away the target changeset (issue2220) When a changeset is skipped, rebase keeps the previous target as next target and if the skipped cset is the first one, the recorded target is actually the original target. --abort did not detect this situation but simply stripped away the cset.

test-branch-option: Updated output to match rev 3f1409082720

Merge with mpm

discovery: fix description line

Merge with stable