Final changes to build process for prebuilt windows files, documenting user configuration options, enabling clsql-lib load paths and some installation manual edits

Check for cross-store loading errors in multi-store operation; more documentation; backend language to data store language

Significant documentation string and documentation edits towards 0.6.1 manual.  Clean up packages so elephant exports user visible symbols and backend exports backend-relevant symbols.  Change required fix in serializer packages also.  Added :elephant-user package.

Export btree utilities; implement efficient map operators, reimplement get-instance methods; add test of map-index; better declarations

Latest changes to launching deadlock processes, all lisps supported (but not tested) except lispworks

Integrated Henrik's changes, except for the sbcl/%bignum-ref in serializer2.lisp which I believed we fixed by importing it from :sb-bignum

Fixed bug from last checkin; implemented abstraction for fast-locks for systems that have such a thing (such as without-interrupts in non-parallel lisps)

Up and limping; 0.6.1 working HEAD is in good shape again.  Fails four tests (all cursor ranges).  Object ID's are turned off for now - they are a user configuration option

Removed config.lisp and all Makefile related build options.  The build is
now entirely driven from the elephant.asd and ele-bdb.asd files with a
simple user customization file, config.sexp, that should be copied to
my-config.sexp and customized to the user's environment.  Thanks to
pinterface for the initial patch supporting this approach.  Foreign
library loading is also controlled from the asd files now at system
load time rather than at compile time.

Significant additions to the 0.6.0 release on the trunk.  Updates to
documentation, 0.5.0 compliance, final on 0.6.0 features.  There are
one or two BDB interactions on migration to work out but this should
be a nearly code complete 0.6.0 release.  Please start testing and
evaluating this - especially the ability to open and tag 0.5.0 databases.

Features:
- Database version tagging
- Support for 0.5.0 namespaces & databases
- New migration system
- class indexing without slot indexing
- various bug fixes
- reverted fast allegro/sbcl string support to
  allow 0.5.0 databases to work correctly.  I
  couldn't find a good way to work around this
  without creating infinite headaches
- validated that running db_deadlock will stop all
  lisp freezes that I've encountered.  This has to
  be run each time a DB environment is opened/created
  so eventually should be made part of the open-controller
  functionality for the BDB backend

Includes most SQL fixes - works under SBCL/ACL.  Two problems remain in indexing under SQL for both SBCL/ACL