With the About info added, `getProfileStatsContext()` need not redundantly add
`"channel"`, `"version"` or `"region"`.
Slightly improve the efficiency of `LlsdToJson()` and `LlsdFromJson()` by
preallocating the known size of the source array or map. (Unfortunately the C++
`LLSD` class offers us no way to preallocate a map.)
In `LLAppViewer::getViewerInfo()`, avoid immediate successive calls to
`gAgent.getRegion()`.
(cherry picked from commit f4b65638879c10c832b3bb8448f82001106ffd11)
* Enable /permissive- on MSVC for better C++ conformance and fix related errors
* Clean up left over warning suppressions from old library or msvc versions
Andrey Kleshchev