v1.21

v1.21 (30th September 2019):

• Fix bug where token pasting two numeric tokens did not yield a numeric token. Thanks
  to Sei-Lisa for reporting this.

• BREAKING CHANGE: Paths emitted by pcpp into #line directives now are relative to the
  working directory of the process when Preprocessor is initialised. This includes
  added search paths - files included from those locations will be emitted with a sequence
  of ../ to relativise the path emitted. If no path exists between the working
  directory and the path of the file being emitted, an absolute path is emitted instead.

  If you wish to disable this new behaviour, or use different behaviour, you can
  customise the new rewrite_paths member variable of Preprocessor.

• Fix bug where __LINE__ was expanding into the line number of its definition instead
  of its use. Thanks to Sei-Lisa for reporting this.

• Add --passthru-magic-macros command line option.

• BREAKING CHANGE: The PreprocessorHooks and OutputDirective interface has
  changed. One now must specify the kind of OutputDirective abort one wants, and one
  can now both ignore AND remove directives. on_directive_handle() and
  on_directive_unknown() now take an extra parameter precedingtoks, these are the
  tokens from the # up to the directive.

• Fix a corner case where FUNC(void)foo() expanded to voidfoo() and not
  void foo() which is a very common non-conforming extension of the C preprocessor.
  Thanks to OmegaDoom for reporting this.

• Add tokens for all the C operators, to help implementation of an expression evaluator.

• Updated embedded ply to HEAD (2019-04-25)

• Fix #include not working if no -I parameters were supplied. Thanks to csm10495
  for reporting this.