Merge lp://qastaging/~hingo/drizzle/drizzle-new-pandora-pluginini-keys into lp://qastaging/~drizzle-trunk/drizzle/development

In order to document auth_ldap (part of https://blueprints.launchpad.net/drizzle/+spec/docs71-focus-areas) I ended up doing changes to the build system so that a script and some openldap schema files become part of a make install. This is needed so an end user can get them without downloading Drizzle sources.

This branch contains the change throughout the build system, including classifying the files with new pandora plugin.ini keys so they are installed by make install. This is ready for testing and merging into trunk. We'll work on the documentation in another branch.

More details from the commit message:

This does 2 things:

1) Modify pandora-plugin to allow more keys in a plugin.ini. Until now
you could only specify headers, sources and extra-dist, but not
scripts (that are not compiled, just copied) or various text or data
files you wish to be part of an installation.

The new plugin.ini keys correspond to automake targets as follows:

# plugin.ini key
automake variable
-----------------
# scripts or bin_scripts
dist_bin_SCRIPTS=
# sbin_scripts
dist_sbin_SCRIPTS=
# libexec_scripts
dist_libexec_SCRIPTS=
# pkg_scripts
dist_pkgdata_SCRIPTS=
# data
dist_data_DATA=
# pkg_data
dist_pkgdata_DATA=
# sysconf_data
dist_sysconf_DATA=

2a) Uses the new keys pkg_scripts and pkg_data to move some useful
files from the auth_ldap plugin to ./share/drizzle7/ so an end user
can benefit from them without downloading Drizzle source codes.

2b) Also adds libdrizzle-2.0/libdrizzle/mysql_password_hash to programs
that should be installed and changes the name to drizzle_password_hash.
(Source filenames are unchanged. Makefile first builds mysql_password_hash
and then makes a copy to the final name. I didn't know if someone expects
mysql_password_hash to be there in some tests or something.)

The intent is to write documentation for LDAP authentication that uses
bin/drizzle_password_hash and share/drizzle7/* for creating LDAP user
records.