Changes since version 1.6
    - Values in the return statement of MSPfunc are allowed.
    - Functions in MSPfunc can now be in PGLEc if the whole program is in PGLEc.

Changes since version 1.5
    - bugfixes and adjustments

Changes since version 1.4
    - MSPea possible with threadsim.
    - several fixes and adjustments
    - Improved eval execution in MSPea.
    - MSPfunc: MSP with functions (based on eval).

Changes since version 1.3
    - several bugfixes

Changes since version 1.2
    - HMPPVis: HMPPV with inverse select.
    - Thr: fork for threads
    - Loading of multiple instruction sets (ie -P PGLEc:Thr)

Changes since version 1.1
    - Generic: can now be 'executed' for testing purposes

Changes since version 1.0
    - MSPea: extension of MSP with eval/apply
    - MSPio: extension of MSP with I/O
    - generic compiler
	- modules for compiling PGLEc with MSPio to Parrot (Virtual
	Machine for Perl 6).

Changes since version 0.6
    - Molecular Scripting Primitives (MSP)
    - several bugfixes
    - reorganisation of code

Changes since version 0.5

    - parallel simulator
    - focus method notation (FMN) and co-programs
    - PGLEcw (PGLEc with while loops)

Changes since version 0.4

    - Support for the unit operator.
    - generic parser
    - generic simulator
    - PGLA jump optimizer

Changes since version 0.3

    - Simulators are provided with the option -g for a graphical user
      interface.
    - Garbage collection (rgc, fgc) can be interrupted.

Changes since version 0.2

    - Full implementation of the null.
      The simulators have an option -n for not showing the null foci in
      the graphical fluid.
    - Values are displayed as plaintext in the graphical fluid so that
      prints of this fluid show these values correctly.
    - A few bug fixes.
