implement combo config parser

allows all options to be overridden by command line.

e.g.
[watchd]
threads=10
debug=false

--watch.threads=50 --debug=true

config.ini.sample

@@ -1,9 +1,8 @@
-[global]
-tor_host = 127.0.0.1:9050
+[common]
+tor_hosts = 127.0.0.1:9050
 database = proxylist.sqlite
 
-[watcherd]
-proxy_file = false
+[watchd]
 max_fail = 5
 threads = 10
 timeout = 15
@@ -11,10 +10,9 @@ submit_after = 200
 use_ssl = false
 debug = false
 
-[proxyfind]
+[ppf]
 search = true
 timeout = 30
-threads = 3
 checktime = 3600
 perfail_checktime = 3600