ChangeLog for smooth

19.11.17 17:34 - smooth alpha 0.8.73.0

- surfacecocoa.mm	- fix hangs on macOS 10.11 El Capitan
- fontbackend.cpp	- cache computed text extents
- window.cpp		- added handleSystemMessage callback
- windowgdi.cpp		- don't update coordinates for minimized windows
- windowcocoa.mm	- added support for SetProgressIndicator()
- system.cpp		- added GetResourcesDirectory() method
- mutex.cpp		- added TryLock() method
			- added scoped locker class Lock
			- changed the return type of lock methods to Bool
- semaphore.cpp		- added TryWait() method
			- added scoped locker class Wait
			- changed the return type of lock methods to Bool
- rwlock.cpp		- added scoped locker classes LockForRead/LockForWrite
			- changed the return type of lock methods to Bool
- jpeg.cpp		- avoid temporary files when reading JPEG data from memory
			- check for JPEG signature before trying to open files
- png.cpp		- check for PNG signature before trying to open files
- crc32.cpp		- added method to calculate CRC on plain UnsignedByte * buffers
- crc64.cpp		- added Hash::CRC64 class to calculate 64 bit CRCs
- string.cpp		- added ComputeCRC64() method
- datetime.cpp		- reworked DateTime interface and implementation
- http.cpp		- use libcurl for HTTP transport
			- added support for HTTPS
- listentry.cpp		- added static member: tabDelimiter, use it to delimit list entry tabs
			- tab delimiter changed from horizontal to vertical tab character
- cursor.cpp		- performance improvements
- tipodaydlg.cpp	- tips can now be marked and copied

- ported to Haiku OS
- removed support for QNX
- upgraded libjpeg to version 9b
- upgraded libpng to version 1.6.34
- upgraded libxml2 to version 2.9.7
- upgraded zlib to version 1.2.11
