Fixed the locale issue where I18n.locale overrides he_IL to he-IL

[itayadler]

• The gem gettext_i18n_rails had a behavior where each time a locale was set on I18n.locale, it would dasherize the locale. I've added a monkey patch to the gettext initializer that solves this issue.
• Changed log level to debug for development

[itayadler]

This relates to #9

[crowbot]

Hello, just to note that I recently made a commit to core Alaveteli to fix the same bug - https://github.com/mysociety/alaveteli/commit/8c8ff1c840451c9ed598c1b8c68ed72a1a938a38#L0L167

[itayadler]

Sry didn't have time to attend this.