New insight: Top Words

Added stemmer lib and stemming function to Utils.

closes #2020, closes #2149
Top words: Correct days of week
Clean up meta tags
InsightTerms: Avoid "You've it good" swapInSecondPerson bug

Drop “has” from Follow Count Vis insight headline
Added style guide to documentation. Updated buildinsight with link to
style guide.
Added percent symbol to alternate text for AgeAnalysis.
Add InsightPluginParent::shouldGenerateAnnualInsight
Add InsightPluginParent::shouldGenerateEndOfYearAnnualInsight
Added getThisYearOfPostsIterator to PostDAO
Added iterator argument to PostDAO::getALlPostsInRange
Added iterator argument to PostDAO::getAllMentionsInRange
New insight: Thanksgiving Who You Thanked insight
Thanksgiving Who Thanked You insight
Thanksgiving insight tweaks

Remove action button
Add link to conversations
Add TimeHelper::getDaysSinceJanFirst
Issue #2136: Most replied-to/commented-on post; End of Year

Added shouldGenerateEndOfYearAnnualInsight; ready to go