Update Floater World Map, add support for worldmap and maptrackavatar slurls (Find on map and show pick on map in web profiles)

Cleaned up includes, switched callbacks over to mCommitCallbackRegistrar, updated RLVa portions to RLVa 1.4.5, changed mSLURL from a string to a real SLURL
Optional V3 Web Search and support for search SLURLs

Added "Use web-based search instead of legacy v1 search" checkbox to System->General preferences

Unified all functions to display search floater into toggle_search_floater and LLFloaterSearch::showInstance
Added UseWebSearch and UseWebSearchSLURL debug settings for flexible configurations
- SLURLs with legacy search cannot always present the same results as web
Added SearchURL debug setting, a separate setting from the one used in the all tab, slightly different and always set by response["search"] on OSGrid logins to detect if websearch is supported
Cleaned up llfloaterdirectory includes and added "Search.WebFloater" to the CommitCallbackRegistrar in case we ever want to add a button or something to open web search (couldn't find a nice place for it, sadly), also added more functions to show specific tabs and performQueryOn to search a tab with specific query on LLPanelDirBrowser's
Fix Issue 630: Appareance to XMl don't work

Removes the enable callback for Appearance To XML, LL no longer has that hooked in, why should we?
Tested and confirmed to work with or without DebugAvatarAppearanceMessage the same way.
Fix Issue 706: 4000Alpha terrain downloads fail
Fix two bugs for web search

1. When web search was open, because it had no id, it would steal the links clicked for the in-viewer browser, now it identifies as search and will not.
2. Work around an oddity with the browser being unresponsive to certain category only slurls, by temporarily removing the expected behavior of it returning as last seen when reopened (no setVisible(false) in onClose, just close out as normal)
Merge branch 'master' of https://github.com/singularity-viewer/SingularityViewer
Solve Issue 907: Build -> Objecttexture -> Searchfield-activation