Add potx to Multilanguage package

I'd more likely put it to Multilanguage as suggested for my similar modules, such as l10n_client: #373404: Move module to category Multilanguage Even though you'd use this module in the development phase of a site, being a Multilanguage support module is more reflecting of the characteristics of the module.

http://drupal.org/node/231036 says

If your module comes with other modules or is meant to be used exclusively with other modules, enter the name of the package here. If left blank, the module will be listed as 'Other'. In general, this field should only be used by large multi-module packages, or by modules meant to extend these packages, such as CCK, Views, E-Commerce, Organic Groups and the like. All other modules should leave this blank. As a guideline, four or more modules that depend on each other (or all on a single module) make a good candidate for a package. Fewer probably do not.

If used, the package string is used to group modules together on the module administration display; the string should therefore be the heading you would like your modules to appear under, and it needs to be consistent (in spelling and capitalization) in all .info files in which it appears. It should not use punctuation and it should follow the Drupal capitalization standard as noted above.

So there are some points against abusing the package name for modules not actually working together. In this case potx works with coder module for code review support as well as l10n_server for parsing of source code. So it both has ties to development and multilanguage.

I believe that as a "package" it belongs more to the multilanguage package then development.

Yeah, well, adding on Development would create a one item category for those who only have this one from that package. Anyway, I decided to add it to the Multilanguage package at the end and committed that change.