Age analysis insight: Make the headline second-person friendly
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
Issue 2133: Most favliked post this year

Added daysSinceJanFirst Utils method

Issue 2133: Most faved/liked post this year

Updated with shouldGenerateEndOfYearAnnualInsight