minor changes for 2.1.0-rc1 release.

Make ServerSelectionTimeout configurable via an environment variable …

…and change the default value to 10 seconds in DriverTestConfiguration also.

tagging 1.10.1

bumping version.

Change tests that use dropDatabase to use small databases.

changing rc1 to rc0.

CSHARP-1117: Rename MaxPoolSize to MaxChunkCount in BsonChunkPool.

updated release notes.

fixed build script to incorporate new MongoDB.Driver.Legacy project.

tagging v1.10.0