Allow multiple pre hook scripts

[tuxmaster5000]

In many scenarios it will be much simpler to use more simple script instant of one big script.
For example, one for reject binary check in, an second for syntax check etc.
Doing it all in one script will result in much double code, because for example you will need the "binary block code" in every script.

[kovetskiy]

Yes, that makes sense, although I'm not sure that it's really technically possible in terms of Bitbucket
API extensibility.

I'll check and get back to you.