Using an external cJSON installed under /usr/include was not possible before
as the cJSON headers within opm were still used due to relative paths.
With this commit move the copied cJSON source to external/cjson and
thus prevent them to be found if an externally installed cJSON is there.
This is an effort to improve build performance. Several includes
scattered across the project are either unused or partially used (i.e.
just used to import a type name, not depending on the actual contents of
the header file).
Replaces a lot of these includes with forward declarations.
- use a opm-macro to reduce code duplication
- add a 'test-suite' target which builds tests. for use if BUILD_TESTING
is 0.
- add a 'check' target which builds tests, then executes them
this is just the result of
```
find -iname "*.[ch]pp" | xargs sed -i "s/ *$//"
find opm/parser/share/keywords -type f | xargs sed -i "s/ *$//"
```
so if it causes conflicts with other patches, the others should get
priority. The rationale behind this patch is that some people tell
their editor to remove white space which leads to larger than
necessary patches...
i see no reason to keep the separate library and this circumvents
shared vs static linking issues.
an alternative fix is to fix the opm buildsystems to prioritize config
mode. that would be more involved.
- probe only for system lib (i.e. only probe in prefix paths)
old code ended up not installing the json lib due to finding a copy
in the build folder if a reconfiguration was performed.
- build internal copy static and bundle in libopm-json.so
no reason to install this as a shared library. if it is updated
originating from opm, the entire parser library is updated anyways.
these includes are required by the headers. If the affected files
would have been included without the headers included before, a
compiler error would have been produced.
