pear: fixes crash on invalid utf-8 sequence

The `pear info` command may return some invalid utf-8 chars (like it does for `pear info drush/drush`).

Piping the command output through `iconv -c` solves the thing.

This solves #68
Fix tests for pear::module
Fix typo in pear_module_spec
Merge pull request #69 from feychenie/patch-1

pear: fixes crash on invalid utf-8 sequence