One more widget type, added HipChat and Bamboo DAOs, trend colors improved

Added:
1. "Incremental graph widget" - perfect for NewRelic free account. Since fetching metric history is unavailable for this account, "incremental graph widget" can collect data and draw charts on the fly based on live data from NewRelic. Moreover, it supports other chart types, blinks when metric value exceeds its threshold value and has improved trend colors (red for aggravating trend, green for improving trend).
2. "HipChatDAO" - allows dashboard to display messages from HipChat rooms. It uses existing "message widget".
3. "BambooDAO" - allows dashboard to display build status from Atlassian Bamboo platform.