Define open_(o|i)fstream_and_log_error in log.h to:
- quote 'filename'
- add error cause to easier troubleshoot
- use existing consistent string style
- easily allows OS specific message
Introduce it when file are opened and add it where error message
was missing.
Two user-visible changes were made:
* `-DUSE_RUST` is replaced with `-DBUILD_RUST`, by analogy with
`-DBUILD_PYTHON`
* `-DCOVERAGE` was removed as it doesn't work with either modern GCC
or Clang
bel bindings should be updated with bindBel/unbindBel during placement, or setting the BEL attribute for constraints before placement.
Fixes#522
Signed-off-by: gatecat <gatecat@ds0.me>
