CLI: automatically fetch FPS from movies whenever suitable

This commit deprecates "-A, --auto-fps" switch. It added unnecessary complexity. FPS are now fetched
whenever it's suitable i.e. when movie is specified by user (via -v switch) or where there is
automatically found a movie for subtitle (practically when it has the same basename as subtitle
file, but with a different extension). FPS is not automatically detected whenever user gives it via
--fps switch. When Subconvert is unable to auto detect FPS, it uses some default value.

Note that it only changes CLI version behaviour. Users can still set in pfiles their preferences
about automatic FPS fetch and CLI will respect them.

-A switch is not removed yet. Instead Subconvert will print a message informing user about its
deprecation. It will be removed in the next major release.

subconvert/cli/MainApp.py

@@ -62,7 +62,7 @@ def getFps(self, subFile):
         fps = self._args.fps
         if fps is None:
             fps = self._args.pfile.fps # default value
-            if self._args.autoFps or (self._args.video is not None) or self._args.pfile.autoFps:
+            if self._args.pfile.autoFps:
                 movieFile = self._parsePathTemplate(self._args.video, subFile.path)
                 videoInfo = subFile.detectFps(movieFile, fps)
                 fps = videoInfo.fps
@@ -161,6 +161,10 @@ def run(self):
             if len(self._args.files) == 0:
                 log.warning(_("No files selected."))
 
+            if self._args.autoFps is not None:
+                log.warning(_("-A, --auto-fps switches are deprecated."))
+                log.warning(_("  note: FPS is now automatically fetched whenever it's suitable."))
+
             for filePath in self._args.files:
                 log.info(_("Starting a job for file: %s") % filePath)
                 try:

subconvert/utils/PropertyFile.py

@@ -30,7 +30,7 @@ def __init__(self, subFormats, filePath = None):
         self._availableFormats = subFormats
 
         self._autoInputEncoding = True
-        self._autoFps = False
+        self._autoFps = True
         self._fps = 25.0
         self._inputEncoding = None
         self._outputEncoding = None