add package sfml
package sfml: use pkg-config and fix whitespace
package sfml: fix line endings and convert patches to git format
package vtk6: set CMAKE_REQUIRE_LARGE_FILE_SUPPORT
doc update: add note about date portability variable
doc update: add note about patch line endings and .gitattributes
doc update: add note about openssl sha1 to calculate checksum
doc update: add notes about supported toolchains and MXE_TARGETS variable
Makefile: add extra logging details