Added RenamePluginAs in general Purpose Plugin collectors and fix tail csv bug

To make more flexible metric "naming" scheme, I've added a "RenamePluginAs" parameter on each general purpose  plugin  collectors (ie. not closed to a only technology/product).

- tail
- tail_csv
- curl 
- curl_json
- curl_xml
- GenerixJMX.

so you can select "product/plugin" name for each "(File/Instance)" In this way you can  get metrics with tail from system ( and name it as <host>-<systemlog> , and also get metrics from postfix and name it as <host>-<mail>).

NOTE: I've also fixed a bug on the tail_csv plugin when more than one metric defined by File.

NOTE: I've also added this same parameter in the new "apachelog" plugin   released on ( https://github.com/collectd/collectd/pull/576 ) as apachelog format are used by other server products ( WebLogic/HTTP IbmServer/ and other like apache web servers).