Merge pull request #258 from piwik/translationupdates

[automatic translation update] Updated 129 strings in 6 languages (bg, el, es, nb, ro, vi)
Refs #472 Removing $mappingFromNameToId as it seems unused
Add send mail hook more than once now that extra observers are cleared.
Fix tests
Refs #472 Define event metrics translations in new hook
The [Debug] section is overwritten by tests. Instead use a new [DebugTests] section that will not be overidden (in Config->setTestEnvironment)
Refs #472 Moved events translations from core translation file to plugin
Fix build
Fix build
Updated translation
refs #4967 started to work on verifying plugin version during run time and before update. Not 100% tested yet, especially not the updater yet
refs #4967 actually disable plugin during update if needed
Do not modify configCache when overriding session handler for travis build.
refs #4967 display missing requirements a bit more consistent
Merge branch 'master' of github.com:piwik/piwik
Do not send header on CLI mode.
Merge remote-tracking branch 'origin/master'
Fixing a classic bug. let's see if any test fails the build.
Refs #472 Custom Events Archiver and API
Merge branch 'master' of github.com:piwik/piwik