Test Release 4.7-beta1

This is a test release for the upcoming version.

Language changes:

• Adds SIO statement
• Adds Fujinet support: NOPEN, NCLOSE, NSTATUS and NGET statements, see "nc" and "mastodon" examples.
• Support ADR for floating point variables.
• Adds %() function.
• You can now omit parentheses in string functions, like LEN "X" instead of LEN("X")

Fixes:

• Fixes compiling long DLI statements.
• Fixes for AND/OR mixing bools and integer operands.
• Fixes chaining COLOR() and RTAB() in PRINT statements.

Cross Compiler:

• Fixes on Windows cross compiler for filenames with spaces or Unicode characters.
• Better error messages:
  • show variable names in errors,
  • ASCII art with the error location,
  • shows errors on missing ending of loops or ifs.