Drop all references to the FAQ
Add bit about lloadd.conf
regenerate text based INSTALL file

This commits deletes all references and code for back-bdb and back-hdb.
There is some follow up work still necessary to flush out the admin
guide for back-mdb.

* Align INSTALL and doc/guide/release/install.sdf, so
  INSTALL = (sdf -2txt doc/guide/release/install.sdf) + copyright.
* Autoconf recommends './configure var=val' over 'var=val ./configure'.
* Add -W,-rpath,<path> to an LDFLAGS example.

update misc notices

Also, pass empty_bv when bv_val is NULL.