core: Allow arbitrarily large config values
core: Upgrade config schema on install to allow arbitrarily long config values
core: check type of value column in config table before upgrading.
Merge branch 'hanikesn-increase-size-of-config-values'

Fixes #638.
core: Read site config also from files in site config.d.

Site config options are now derived from the files (in order, where options may be overridden by a later file):

priv/config => site/<sitename>/config => site/<sitename>/config.d/*

Where files from the config.d directory is read in alphabetical order, ignoring those beginning with . or ending with ~.
These files are usually backup or other irrelevant files.

Fixes #648.
core: add Jarimatti V to list of CONTRIBUTORS.
core: update CONTRIBUTORS

Oh, it was a sorted list..
core: avoid duplicate entries in site config.

Resulting from parsing multiple files in the site's config.d directory.

Fixes #648.