projects/README.md PATCH

[smanders]

currently the projects/README.md file is cmake-generated (at cmake-time) from the contents of the projects files themselves

the patch/diff column is populated if the PRO_FOO variable has DIFF, GIT_REF and GIT_TAG values - otherwise "none"
https://github.com/smanders/externpro/blob/18.01.1/modules/xpfunmac.cmake#L615-L624

  if(DEFINED P_DIFF AND DEFINED P_GIT_REF AND DEFINED P_GIT_TAG)
    string(FIND ${P_GIT_REF} "/" slash) # strip off "origin/" from REF
    if(NOT ${slash} EQUAL -1)
      math(EXPR loc "${slash} + 1")
      string(SUBSTRING ${P_GIT_REF} ${loc} -1 P_GIT_REF)
    endif()
    set(diff "[diff](${P_DIFF}${P_GIT_REF}...${P_GIT_TAG} 'patch/diff')")
  else()
    set(diff "none")
  endif()

one of the ideals of externpro was that there should be a repository that had the changesets that make the patch/diff -- that developers could look at the commits that went into making a patch and these commits could be reapplied to future work (branching off a new release tag)

however, there have been multiple externpro-style offshoots (which use externpro for it's cmake) that I've been made aware of that take shortcuts and commit a patch file without a repo to back it up

it would be nice if these manually added patch files could be represented in the projects/README.md patch/diff column

[smanders]

completed with commit to dev branch referenced above