In OpenSSL 1.1.0 and newer, the locking callback macros do nothing.
This causes unused warnings for the static function lock_callback.
Ignore this function on newer OpenSSL builds, but keep
the infrastructure for now.
When OpenSSL's min version is 1.1 or greater, all the locking
infrastructure can be removed.
* Dick Hollenbeck also contributed commit r6440. I inadvertently forgot to set
the Bazaar author tag before I committed it. My apologies.
* Switch to static linking of libcurl and on linux and windows and also
statically link in only required portions of openssl.
* Add the required thread locks which openssl needs.
* Remove the get curl version call from BASEFRAME since it pulls in curl and
openssl into every derived wxFrame class link image.
* Remove curl function from PGM_BASE, switch to atexit() instead. Anything in
PGM_BASE made the singletops bigger.
* Tested on Linux, Windows, and OSX.
* Prevent libcurl from inadvertently being initialized twice.
* Dynamically load libcurl only when required.
* Reduce the number of worker threads when loading footprint libraries to
prevent issues with the GitHub plugin.
1. Fixed an assumption somebody originally made in the plugin that std::string had contiguous storage. This is not specced behavior pre C++11 so we gamble by calling .reserve() which should give a far better guarantee.
2. Added copy to clipboard information for curl
3. Removed some openssl references in compiling.md
4. Renamed struct vars to be uppercase to match "public var" code style policy