GUI: Add too long string literal warning code to theme generation tool.

This has the same effect as clang's -Woverlength-strings warning of
string literals longer than C++ compilers are specified to work with.
GUI: Add code to default theme generation to reduce string length.

The additional code skips the extraneous spaces after the end of an
XML close brace (>) reducing the string literal by 3106 characters,
thus bringing it within the limit for C++ string literals.

Have regenerated the default.inc from scummclassic with this change.
DEVTOOLS: Enable builtin theme in MSVC 2005 and 2008 in create_project.

This reverts commit b830f68bacd18f51f4dd912ce3b54ec47d63f31d as the
builtin theme is less than 64K again.
CREATE_PROJECT: Enable built-in theme for MSVC builds again.

This reverts commit d089658fb84f67652e9569bc03c76bcc65e7b881.
AGI: Adding detection for original AGI Tetris by Peter Kelly.