fix meta data name to etl

This is for the postgresql plugin pushing data through the http write
plugin:

schema to schemaname
table to tablename
index to indexname
Fix flag to set redis server host name
Handle nulls and fix meta data names

Was inserting '(null)' because wasn't handling the case where the json
doesn't have the value we're looking for.  Also fixed the names of the
meta data names.  e.g. schema instead of schemaname.
Handle postgres meta data empty string as null

These values shouldn't be empty strings, not sure where they are coming
from.
Fix a spelling typo in a comment
Update to get meta data for postgresql plugin

collectd v5.0 starts putting the meta data in a different place with the
write_httpd plugin.
Update database creation script

Use a here script to for a COMMIT in case autocommit is disabled.
Update json-c requirement note

json-c 0.9 had a bug when converting JSON arrays of integers to strings.
The 0.10 release seems to have corrected that.
Handle case when request_method is NULL
Move collect example configs

Created a collectd contrib directory.
Add nginx example config
Use HSTORE instead of custom tables

Attempted to simplify the schema and the etl logic by using HSTORE for
collectd meta data.  Also take advantage of the postgres JSON functions
to convert collectd's write_http plugin's JSON output to Postgres
arrays and HSTORE.
Add additional indexes and checks to tables

This is part of the ETL process.  Additional CHECK constraints will
benefit the planner when constraint_exclusion is enabled.  Functional
indexes are added to the postgres plugin tables to help search by meta
data.
Add git ignore file
Update docs and examples
Rename contrib dir to examples
Update README
C99 update for inline functions
create pyramid project for wui
add psycopg req and remove sqlite req