ffmpeg web take 2

This is a more comprehensive/generalized reworking of the last one, it works etc (of course :-).  Note that it adds yet another conf file to the mix, *ffmpeg.webfilters*, which I've assigned to be in the top folder for lack of a better place, which you may want to put somewhere else (note that I haven't added the file itself it to git).  Here's the default annotated *ffmpeg.webfilters*
```
# These are custom rules to fine-tune the behaviour of
# FFmpeg Web Video transcoding with respect to specific urls.  


########################## EXCLUDE ##############################
# urls to be skipped (i.e. passed along to later engines)
#    format:   <regex to match>
#################################################################

EXCLUDE

# unresolved youtube urls
gdata\.youtube\.com|youtube_gdata

# other unresolved urls
feeds\.feedburner\.com
www\.gameswelt\.de
eurogamer\.net
gametrailers\.com
giantbomb\.com
icanhascheezburger\.com
pcgames\.de
winfuture\.de


########################## OPTIONS ##############################
# urls requiring specific FFmpeg options.
#    format:   <regex to match> | <options to add>
#################################################################

OPTIONS

trailers\.apple\.com | -user-agent QuickTime/7.6.2
# uncomment the rule below if you experience audio problems with endgadget:
#www\.viddler\.com | -target ntsc-dvd


########################## REPLACE ##############################
# urls to be modified (using capture groups).
#    format:   <regex to match> | <replacement regex>
#    example: .*somewhere\.com.* | $0\?somevar=true
#################################################################

REPLACE

# no rules yet
```