Minor fixes and enhancements to the SQLITE_ENABLE_API_ARMOR functionality.
Support manually disabling overlapped file I/O for Windows sub-platforms other than Windows CE.
Fixes to the README.md file.  No changes to code.
Redefine the way PRAGMA data_version works:  It continues to change when
any other connection commits, including shared-cache connections, but does not
change if the local connection commits.
Merge the PRAGMA data_version redefinition and other fixes from trunk.