cat: stop using makefileobj() Prepares for porting to the formatter API. We won't be able to utilize the abstraction provided by makefilename() because formatter must be instantiated per file.

formatter: add nullformatter This can be used as a placeholder variable.

formatter: add helper to create a formatter optionally backed by file To make things simple, openformatter() and maybereopen() have no support for a plain object API. Callers must use the "with" statement. Unlike cmdutil.makefileobj(), append mode ('ab') isn't supported by these functions. This is because JSON output can't be simply concatenated. Perhaps cmdutil.export() will have to build a {filename: [revs...]} map first and write revs per file.

formatter: add option to redirect output to file object Commands like 'export' have --output=OUTFILESPEC option, so we need a way to write formatter output optionally to a file.

tests: fix typo in "flagprocesor"

contrib: remove unnecessary debug output from editmergeps.ps1

contrib: fix a bug preventing editmergeps.ps1 from running unknonw editors '$ executable' is not a way to run executable in powershell, '& executable' is instead. Found this when testing with regular Windows notepad.

contrib: make editmergeps use -NoNewWindow option in Start-Process cmdlet Running 'Start-Process -Wait "vim" "+10" "filename"' from PowerShell actually spawns a separate cmd window to run vim in. This looks ugly and in most cases not what user wants. During my initial testing I was using the Cmder app, which made me not notice this (it captures new windows as new tabs).

contrib: run editmergeps.ps1 from the same location as editmergeps.bat This change is needed for cases when user does not put editmergeps.bat directly into PATH, but rather uses 'merge-tools.editmergeps.executable' config option to provide a full path to editmergeps.bat. In such cases, editmergeps.ps1 cannot be run simply by name, it needs a full path. In BATCH file %~dp0 stands for the directory in which the original file is located.

help: pass commands module by argument This removes import cycle.