plugins: make PlayBuf and BufRd tolerant to differing buffer sizes
plugins: make PlayBuf and BufRd warn once on wrong buffer format
help: update PlayBuf and BufRd helpfiles, tolerating buffer mismatch
class library: Tdef inherits its envir when forking and passing an event
class library: insertParent method for IdentityDictionary
class library: quick fix for SerialPort crash. Fixes #862.
Classlib: Pstretchp: Remove erroneous 'asEvent'