- Stick to a single unified way to use structs
 - Make checksrc complain on 'typedef struct {'
 - Allow them in tests, public headers and examples

 - Let MD4_CTX, MD5_CTX, and SHA256_CTX typedefs remain as they actually
   typedef different types/structs depending on build conditions.

Closes #5338

Fine: "struct hello *world"

Not fine: "struct hello* world" (and variations)

Closes #5386

  * runtests.pl:
    - Fix out-of-tree build under CMake when srcdir is not set. Default
      srcdir to the location of runtests.pl.
    - Add a hack to allow CMake to use the TFLAGS option as documented
      in tests/README and used in scripts/travis/script.sh.
  * Bump CMake version to 3.2 for USES_TERMINAL, dropping Debian Jessie
    support (no one should care, it is already EOL.).
  * Remove CTest since it defines its own 'test' target with no tests
    since all unittests are already broken and not built by default.
  * Add new test targets based on the options from Makefile.am. Since
    new test targets are rarely added, I opted for duplicating the
    runtests.pl options as opposed to creating a new Makefile.inc file.
    Use top-level target names (test-x) instead of x-test since that is
    used by CI and others.

Closes #5358

The default target should only build libcurl and curl. Add a dedicated
'testdeps' target which will be used later when running tests. Note that
unittests are currently broken in CMake and already excluded.

Closes #5368

A common set of functions instead of many separate implementations for
creating buffers that can grow when appending data to them. Existing
functionality has been ported over.

In my early basic testing, the total number of allocations seem at
roughly the same amount as before, possibly a few less.

See docs/DYNBUF.md for a description of the API.

Closes #5300

More connection cache accesses are protected by locks.

CONNCACHE_* is a beter prefix for the connection cache lock macros.

Curl_attach_connnection: now called as soon as there's a connection
struct available and before the connection is added to the connection
cache.

Curl_disconnect: now assumes that the connection is already removed from
the connection cache.

Ref: #4915
Closes #5009

Closes #5306

This fixes the error: 'for' loop initial declaration used outside C99
mode by declaring the loop increment variable in the beginning of the
block instead of inside the for loop.

Fixes #5254
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>

Our code style mandates we put the conditional block on a separate
line. These mistakes are now detected by the updated checksrc.