Use g_uri_list_extract_uris when a file is dragged and dropped

When files are dragged and dropped into GHex, the drag data comes
through as text/uri-list. This media type is described by RFC 2483 and
can actually be quite complex, with CRLF at the end of every line and
optional comment lines interspersed with the data. Without using the
right function to parse this data, GHex shows an error message when
dropping files from PCManFM to GHex.

https://bugzilla.gnome.org/show_bug.cgi?id=679717
Release 3.5.2
Don't use GDK_THREADS_ENTER/LEAVE

We're not calling gdk_threads_init, so ENTER/LEAVE are no-ops
anyway.

https://bugzilla.gnome.org/show_bug.cgi?id=681253
[l10n] Update Japanese translation

Merge latest pot
[l10n] Update Japanese translation

Modify the About label
Add missing license headers
Makefile.am: Sort the source file list
Port to GtkApplication

Make GHex a non-unique GtkApplication; this is a
prerequisite for recent desktop integration features.
window: Inherit from GtkApplicationWindow instead of GtkWindow

This is necessary to make use of the new GMenu API.
build: Automatically generate dependencies for ghex-resources.c
Updated Polish translation
Release 3.5.90
Updated Polish translation
Updated Hungarian translation by Balazs Ur <urbalazs at gmail dot com>
Remove .gitignore from source control

We have git.mk generating .gitignore; keeping it under version control
will only cause trouble when the generated file changes.
Add GtkHexPrivate structure for private data

The motivation for this is to get a private structure where we can add
and remove fields without worrying about breaking the library ABI.

This also includes a change to the GtkHex public struct: the pointer to
disp_buffer in the public struct is replaced with a pointer to
GtkHexPrivate. Removal of disp_buffer however shouldn't affect any of
the library clients as neither of them accesses it directly; replacing
it with another pointer will also keep the struct size unchanged to
preserve the rest of the ABI.
Fix gtk_hex_set_geometry() to work for sizes less than 16x16

This fixes the initial size for GHex's Edit->Find window and also gets
rid of the ugly double scrollbars in Nemiver's memory view widget.
Release 3.5.91
Updated British English translation
Release 3.6.0