[RPL/2] RPL/2 4.0.0.prerelease.4

[BERTRAND Joël]

	Hello,

	Now, RPL/2 can precompile scripts ! Try -p option.

	Error returned by preprocessor are now catched by RPL/2. -p option is 
added. With this option, all scripts are compiled before RPL/2 starts 
evaluation. HALT cannot be used with -p, but all programs run
40% faster. Read and write operations in pipe() are rewritten to be sure
that such operations are atomic. Some other bugs have been fixed.

	JKB