4.4 Improve --data-urlencode space encoding
5. Build and portability issues
+ 5.1 OS400 port requires deprecated IBM library
5.2 curl-config --libs contains private details
5.3 curl compiled on OSX 10.13 failed to run on OSX 10.10
5.4 Build with staticly built dependency
5. Build and portability issues
+5.1 OS400 port requires deprecated IBM library
+
+ curl for OS400 requires QADRT to build, which provides ASCII wrappers for
+ libc/POSIX functions in the ILE, but IBM no longer supports or even offers
+ this library to download.
+
+ See https://github.com/curl/curl/issues/5176
+
5.2 curl-config --libs contains private details
"curl-config --libs" will include details set in LDFLAGS when configure is