fcm branch create: alternate interfaces

[matthewrmshin]

The command line interface of branch create has confused some users as it uses the project URL as an argument - as well as taking many different options. Alternate interfaces are recommended:

# Current interface
fcm branch-create [OPTIONS] NAME [PROJECT-URL]
# New interface 1
fcm branch-create [OPTIONS] BRANCH-URL [...] [PARENT-URL]
# New interface 2
fcm branch-create [OPTIONS] TICKET-NUM [...] [PARENT-URL]

In the 1st new interface, the argument list will be a list of URL of the branches to create. Each of these must conform to the FCM branch naming convention. The final argument will be the parent URL. (This argument is optional if the current working directory is a working copy to the parent URL.)

In the 2nd new interface, the argument list will be a list of ticket numbers. This is similar to the current usage, except that the final argument will be the parent URL, and the options --rev-flag=NONE will be automatic, i.e. the resulting branch path will look like branches/dev/fred/1234.

[matthewrmshin]

No demand