make masterdir configurable via configure option: --with-masterdir=<directory>
append masterfiles when CFENGINE_TEST_OVERRIDE_WORKDIR environment is set
sys.inputs is configurable via:
 * ./configure --with-inputdir=<directory> (default: sys.workdir/inputs)
Use the new functions
 * GetInputDir() for inputs directory (sys.inputdir)
 * GetMasterDir()  for masterfiles directory (sys.masterdir)
Warnings
Make prep step and output render correctly as code.

Everything in a #@ block is rendered verbatim, ie interpreted as
markdown.
Mark preparation steps and output in all example files as code.
examples/remake_outputs.pl: skip Markdown outputs
examples/remake_outputs.pl: skip Markdown outputs in outputs, too
examples: fix up examples for acceptance test and print old output when different
examples: more fixes for acceptance tests
examples/remake_outputs.pl: run diff if outputs differ
examples: even more fixes for acceptance tests
examples/filestat.cf: fix for acceptance test
18_examples/check_outputs.cf: reenable
examples/lsdir.cf: sort filenames
Expand related first-pass cleanups
examples: adjust ip2host.cf test
examples/classesmatching.cf: add new output class to output
String input to ExpandAndMapIteratorsFromScalar is mutated, not const