A brief explanation of what have been implemented. More information can be found in comments.

1. Created conversation history viewer (llfloaterconversationpreview)
2. Created LLConversation and LLConversationLog classes which represent and hold data of conversations (llconversationlog)
3. Created LLConversationLogList and LLConversationLogListItem which are the visual representation of LLConversationLog and LLConversation respectively
4. Created LLFloaterConversationLog - which holds and displays LLConversationLogList

- Increased min width of conversations panel by 10 pixels

- Removed code which was hiding floater on minimizing floater.

also improved selection behavior for object contents when deleting/adding items

CHUI-206 FIX Viewer crash when selecting to cut inventory item, then selecting to cut another inventory item
Seems to work now, without filtering de-optimization

CHUI-211: Problem was due to a non-heap variable being deleted and then referenced later (which was found by ProductEngine). Also the crash occurred at a specifc location llpangelobjectinventory::reset() during a static_cast, so now using a dynamic_cast as a safeguard.

The old display name should be cleared before refreshing the views for both items and folders in folder view, otherwise the old name will be used upon renaming.

cleaned up serialization of LLSD to param block so that it can round-trip
also, optimized LLXMLNode and fixed an assert

CHUI-229 [FIXED] Nearby chat conversation does not appear initially in conversation list if no other conversations are present

CHUI-231, CHUI-233 [FIXED] - Modified and simplified algorithm of reshaping floater's body (content)  and showing/hiding of the title for prevent of present and future issues with floater's repositioning

CHUI-236 : WIP : Places panel works for My Inventory but still empty lists for Favorites Bar, My Landmarks and Library.

CHUI-236 : WIP : Modify the handling of FT_ROOT_INVENTORY which was creating havoc in LLInventoryModel instantiation. Still, some of those hack will have to come back on.

CHUI-206 FIXED Viewer crash when selecting to cut inventory item, then selecting to cut another inventory item

Each conversation item is added to the folder view which lists all conversations.

CHUI-170 Workaround for the permanently showing of the nearbychat's name in a conversations list when that floater is torn-off

Fixed the problem with confirmLeaveCallCallback() firing after the chat floater is destroyed.