scanbd Code

- Make scanbuttond_backends_dir accept also relative paths (starting from scanbd etc dir)
- Make scanbuttond_loader understand libdir and confdir for backends
- Rename CFG_DIR to SCANBUTTOND_CFG_DIR

Fix scanbd config file for when SCANBD_CFG_DIR is not set. Remove leading /

Updated scanbd.conf for the scriptdir option
Reformatted scanbd.conf from tabs -> spaces

- Added opton "scriptdir" in general section of the scanbd.conf.
scriptdir is either a relative path (from the scanbd config dir)
or an aboslute path
- made script option in the action session either
- absolute (starts with /) or relative to scriptdir (if defined)
- Update of scanbd.conf sample is still to be done

Fix issue where scanbuttond was build always, regardless of whether --enable-scanbuttond was used

Added checks recommended by autoscan to configure.ac

Corrected some bugs in Makefile.am's that caused scripts not to get installed

Add files missing after direcory restructuring to svn

Major reorganiation of the directory structure
Separate src, conf, scripts etc subdirectories

fixed Makefile.simple for target test to produce testscanbuttond if using USE_SCANBUTTOND=yes