(framework, fuse, kext) Use __APPLE__ instead of (__FreeBSD__ >= 10)

Use macro __APPLE__ instead of abusing macro __FreeBSD__ to identify Darwin.
(kext) Fix compiler warning/error in case of non-debug build
(fuse, macfuse) Update libosxfuse and libfuse/libfuse_ino64

* Update libosxfuse to version 2.8.0

* Use independant libfuse/libfuse_ino64 2.7.3 libraries for MacFUSE instead of
  libosxfuse adapter. These libraries guarantee compatibility with the latest
  official MacFUSE release: 2.0.3/2.1.5.

* Drop libosxfuse_i32 because it is not longer needed for the MacFUSE
  libosxfuse adapter.
Add build target "kext"

Target "kext" builds the OSXFUSE kernel extension for a specific platform.
Rework build target "reload"

Target "reload" is just a wrapper for target "kext". It unloads the kernel
extension, builds target "kext", and reloads the newly built extension.
Add parameter "install_to" to function "m_build_pkg"

This parameter allows to specifiy the install prefix for the payload of an
installer package.
Introduce new "fat" file system bundle

* (kext) The "fat" file system bundle contains all individual builds of the
  kernel extension for Mac OS X 10.5, 10.6, and 10.7. The builds are located at:

  osxfusefs.fs/Support/10.[5-8]/osxfusefs.kext

  The load_osxfusefs tool automatically pick the kernel extension matching the
  currently running version of OS X.

* Add build target "osxfusefs" that builds the "fat" file system bundle.

* Target "smalldist" does no longer build a "small" core package for just one
  version of OS X. The new core package works on all supported versions of
  OS X and includes the file system bundle osxfusefs.fs, the user space library
  libosxfuse, and OSXFUSE.framework.
(fuse, macfuse) Fix Makefiles for example file systems
Rename build target "smalldist" "core"
Add build target "release"

* Rework target "dist". "dist" used to create the the OSXFUSE distribution
  package OSXFUSE.pkg, the wrapping disk image OSXFUSE-{version}.dmg, and the
  signed updater file (Current|Developer)Release.plist.

  Creating the diskimage and the updater files has been moved to the new build
  target "release". This is done to simplyfy building a OSXFUSE installer
  package without the overhead of creating a disk image or having to provide a
  signing key. Most of the time these additional steps are not needed.

  To build the OSXFUSE installer package run the following command in the cloned
  repository:

  ./build.sh -t dist

* Update copyrights

* Bump version of build tool to 2.0
Don't build the "Redist" package

The "Redist" package has never been used and has become obsolete with the
introduction the "fat" file system bundle. Now, there is just one core package,
which can easily be included in third-party distribution installer packages.
Some minor cleanup
Update License.rtf in release disk image

See commit d5754efc687d456ea80ed13e39997ee928094f98.
Fix MacFUSE Compatibility Layer detection in uninstaller
Sign installer package for Gatekeeper

* (target release) The signing identity can be specified using option -i. If no
  signing identity is specified, try to sign the package with the following
  identity:

  "Developer ID Installer: {real name of user}"

* (target release) The key file used to sign the update rules file can be
  specified using option -u. If no key is specified and
  "$HOME/.osxfuse_private_key" does not exist, use the test key
  "./prefpane/autoinstaller/TestKeys/private_key.der".

  Note:

  The private key is used to sign the file CurrentRelease.plist or
  DeveloperRelease.plist (in case of a beta release). These files represent the
  server-side of the update mechanism. Using the test key has no impact on the
   resulting binaries or the ability to update OSXFUSE.
Update copyright in licence
(fuse, kext) Implement ABI version 7.12
Fix help message of build script
Fix download URL in (Current|Developer)Release.plist
Fix bug in detecting source root