Allow specifying file name and format as cmd args for freeze, deduce format from filename#701

tony merged 4 commits intotmux-python:mastertmux-python/tmuxp:masterfrom

dnaaun:add-output-file-and-format-cmdline-optionsdnaaun/tmuxp:add-output-file-and-format-cmdline-optionsCopy head branch name to clipboard