add a copy constructor and assignment operator to TContentHeader, HTttpHeader and TInternetMessageHeader class.
add a copy constructor to THttpHeader class.
added a mkspec: macx-clang
fix a bug of delete processing for tspawn command.
update version string.
Update ChangeLog and INSTALL files.
renamed: substr.bat -> src/trash/substr.bat
renamed: line_replace.bat -> src/trash/line_replace.bat
updated Doxyfile.