Gitignore NEC diagnostic files

See merge request !11

# Conflicts:
#   COPYING

Check for Fortran flag to accept long source code lines

See merge request icon-libraries/libmtime!10

* origin/master: (56 commits)
  Remove unused variable and annotate unused argument.
  Remove unused variables.
  Fix incorrect type kind.
  Remove unused variables from wrappers.
  Fix for changed name.
  Fix typo.
  Declare internal routine as static.
  Clarify assigned value.
  Switch back case of Fortran keywords.
  Fix typo.
  Reduce number of branches in newJulianDelta.
  Simplify computations in julianDeltaToTimeDelta.
  Straighten control flow in localTimeDeltaToJulianDelta_NonStandardTimeDelta.
  Merge divergent code.
  Simplify string building.
  Reduce branching and fix unnecessary heap allocation.
  Simplify code with stack object.
  Prefer branch-free statement.
  Replace looping with direct computation.
  Put temporary on stack in moduloTimeDeltaFromDateTime.
  ...

This reverts commit bfe42f13.

Intentional change

See merge request !5

* This allows inlining, which the compiler must not use for
  extern functions.

Shorten setting of errno.

* Also emphasizes "happy" path and annotates probable problem.