v0.9.0-pre9

• BINDINGS/C++: Added moving ctors
• BINDINGS/C++: Added sail::meta_data
• BINDINGS/C++: Fixed crash on nullptr to std::string conversion
• BINDINGS/C++: Fixed functions names
• BINDINGS/C++: Fixed read_options copy ctor
• BINDINGS/C++: Initialize sail_io fields
• BINDINGS/C++: Move some ctors in read/write options to a private section
• BINDINGS/C++: Remove unnecessary forward declarations
• CODECS: Added GIF
• COMMON: Added 'URL' meta data key
• COMMON: Added EXIF meta data key
• COMMON: Added SAIL_CHECK_DATA_PTR
• COMMON: Added SailMetaInfo
• COMMON: Added UNKNOWN meta data key into switch
• COMMON: Added more error codes
• COMMON: Fix Coverity Scan warning on continuing loop on error
• COMMON: Fix Coverity Scan warning on dead code in switch/case
• COMMON: Fix Coverity Scan warning on missing va_end
• COMMON: Make interlaced_passes 1 by default
• COMMON: Make meta data nodes to contain binary data as well
• COMMON: Removed resolution meta data keys as they're a part of sail_resolution now
• COMMON: Rename 'meta info' to 'meta data'
• COMMON: Rename EXIF, IPTC, and XMP keys to HEX_
• COMMON: Rename X/Y resolution meta info enumerators
• COMMON: Split string and binary meta data values
• COMMON: Update signatures of memory allocation functions sail_malloc/sail_calloc/sail_realloc
• DOC: Added FORMATS.md
• EXAMPLES: Added 'current frame' label in advanced demos
• EXAMPLES: Added Stop button in advanced demos
• EXAMPLES: Fix sail-probe
• EXAMPLES: Fixed compilation issue with SDL2 on Mac
• JPEG: Move the meta info saving code into a helper
• LIBSAIL: Added key_unknown
• LIBSAIL: Fix Coverity Scan warning on printf format
• LIBSAIL: Fix Coverity Scan warning on using freed pointer
• LIBSAIL: Load custom codecs from SAIL_MY_CODECS_PATH
• PNG: Use hardcoded meta data keys for EXIF, IPTC, and XMP tags
• SAIL: Added CMake development configs
• SAIL: Append to ENV{PKG_CONFIG_PATH} instead of overwriting it
• SAIL: Enable PCH on CMake >= 3.16
• SAIL: Enable _POSIX_C_SOURCE as a compiler definition in CMake
• SAIL: Fix setting PKG_CONFIG_PATH on Windows
• SAIL: Include 'jobs' to allow pkg-config find the path to jpeg-turbo
• SAIL: Include src directories only in build time
• SAIL: Increase the magic buffer size 10 -> 16 bytes
• SAIL: Install cmake configs on Debian
• SAIL: Limit the git clone depth to 1 in travis
• SAIL: Make the travis badge fetch master builds
• SAIL: Move context-related functions into context_private.c
• SAIL: Preserve the old CMAKE_MODULE_PATH
• SAIL: Remove SDL2 pkg-config path as it's unused
• SAIL: Simplify list(APPEND) constructions
• SAIL: Split sail.c into separate files
• TESTS: Added meta data integrity testing
• TESTS: Fixed enum type
• TIFF: Set a string to NULL