asterisk13: change some default file locations
- Set data dir to /usr/share/asterisk and use default locations for
everything else.
- This is more in line with FHS and fixes issue #38. Database files are
now written to tmpfs (/var is mounted there). This prevents the
rootfs from filling up. It also prevents the flash to degrade during
constant database rewriting.
- As the data dir changes, so does the location of the sound files. This
commit also takes care of that.
Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>