eg_db_config assumes it runs from source directory

[Jason Stephenson]

Evergreen Version: master as of 20130419/2.4-beta
OpenSRF Version: latest master
PostgreSQL Version: 9.2.4

eg_db_config is installed to /openils/bin. However, its code still makes assumptions that it is being run from the source checkout/tarball directory.

The following console output illustrates this:

opensrf@jasondev:~$ eg_db_config --create-offline
Can't exec "/openils/bin/../extras/eg_config": No such file or directory at /openils/bin/eg_db_config line 275.
Use of uninitialized value $temp[0] in scalar chomp at /openils/bin/eg_db_config line 276.
Can't exec "/openils/bin/../extras/eg_config": No such file or directory at /openils/bin/eg_db_config line 282.
Use of uninitialized value $temp[0] in scalar chomp at /openils/bin/eg_db_config line 283.
Error: /openils/bin/../sql/Pg/build-db.sh does not exist.

I haven't looked into a fix, yet, but our scripts need to be made relocatable, and they should be better organized in the source if they are meant to be run from there, plus runnable once installed.