app: properly initialize more variables
Found by Coverity
app: fix previous commit
app: I actually tested it this time
Add support for both gamma-corrected and linear for all bit depths

- Add new enum GimpComponentType which contains u8, u16, u32 etc.
- Change GimpPrecision to be u8-linear, u8-gamma, u16-linear etc.
- Add all the needed formats to gimp-babl.c
- Bump the XCF version to 5 and make sure version 4 with the old
  GimpPrecision enum values is loaded correctly

This change blows up the precision enums in "New Image" and
Image->Precision so we can test all this stuff. It is undecided what
format will be user-visible options in 2.10.
app: show the dither dialog when converting between linear and gamma

within one bit depth.
app: fix tests after the GimpPrecision enum change
libgimp: add gimp_component_type_get_type() to gimp.def
app: follow the GEGL invert -> invert-linear vs. invert-gamma change

and invert masks using invert-linear and other drawables using
invert-gamma. drawable_invert_cmd_callback() still always uses
invert-gamma even though it can be used on layer masks.
app: port GimpImagePropView's file size querying to GIO
Add SSE3, 4, and AVX gimp_cpu_accel checks
Use gegl_malloc in GimpTempBuf

Which allocates 16 byte aligned memory for SSE code.
SSE2 & SSE4.1 versions of GimpOperationNormalMode

* Add configure checks for SSE intrinsic code.
* Use SSE helper libraries in app/operations to compile
  code with different CFLAGS.
autogen.sh: also look for automake 1.14
app: whitespace cleanup in operations/Makefile.am
app: make gimp_operation_tool_set_operation() more readable
Bug 703218 - Typo in German translation

In Edit/Preferences/Tool Options, mouseover text over 'Set layer or path
as active': replace 'Eben' by 'Ebene'
libgimpconfig: add gimp_scanner_parse_int64()
Bug 683152 - Preview thumbnails in file open dialog causes error in 2.8.2

Port gimp_thumb_file_test() to GIO which seems to get its stat()
calls right on all platforms.
app: start supporting composer ops in GimpOperationTool

If the operation has an aux input, add a combo that allows feeding
it one of the image's channels. This is all work in progress and
and should allow to use any drawable of any image.
libgimpthumb: use GIO_CFLAGS/LIBS not GLIB_CFLAGS/LIBS