Bump the version to 1.8.11

The 1.8.10 tag is taken by the bad release.
Updated Greek translation
autogen.sh: better check for automake and aclocal versions

Using the "-x.y" suffix when calling these tools is not a very good way
to do this because the user might have higher versions which also work.

So we bring the function check_autotools_version() from banshee's
autogen.sh script [1], but slightly modified to work with /bin/sh instead
of bash.

[1] https://git.gnome.org/browse/banshee/tree/autogen.sh

Signed-off-by: Carlos Martín Nieto <cmn@dwim.me>
autogen.sh: don't use the $PROJECT variable

This was a left-over from banshee's check_autotool_version() function.
(We don't use this variable in this project.)
Compilation fix
Use the runtime's timers instead of glib's
Use Task and await for RefreshAsync() and RefreshAllAsync()

This is much nicer to work with and keep us in the right context,
getting rid of the model and view mismatch.

This needs us to increase the sdk level to 4.5.
autogen.sh: fix typo made in 0a36f0864e899fff8f03763164725b94c4256cc2
autogen.sh: use the $CONFIGURE variable for "configure.in" occurrences

There is already a $CONFIGURE variable set to "configure.in", which we
can reuse in some places. This will come in handy in the near future
when we rename configure.in to configure.ac (because it's giving a
warning about this now).
autogen.sh: fix syntax error when checking the $DIE variable

This line was throwing this error:

"122: test: Illegal number: "

Now we use simple concatenation with "x", which is also a good practice
in case the variable to check has spaces in it.
autogen.sh: avoid sed error "read error on stdin: Is a directory"

The following line in autogen.sh was causing an error:

macrodirs=`sed -n -e 's,AM_ACLOCAL_INCLUDE(\(.*\)),\1,gp' < $coin`

"sed: read error on stdin: Is a directory"

This line is supposed to look for occurrences of this macro
in the configure script, however the $coin variable contained
the value ".", not "./configure.in", so the $macrodirs variable
was not being populated. After fixing this, however, the
$macrodirs variable is still empty (because we don't use
AM_ACLOCAL_INCLUDE in 'configure.in') but at least we removed
the red herring caused by the unique real usage of the $coin
variable (it is also used to extract $dr, which is the dirname
of $coin, which maps to "." regardless if $coin is "." or
"./configure.in", so everything keeps working as before).
autogen.sh: rename configure.in to configure.ac to avoid automake warning

The following warning was being thrown by automake:

automake: warning: autoconf input should be named 'configure.ac', not 'configure.in'

By simply renaming the configure.in script to configure.ac we get rid of
it, but we also need to rename the $CONFIGURE variable in autogen.sh so
everything keeps working as expected.
configure.ac: avoid deprecated use of AM_INIT_AUTOMAKE

The way AM_INIT_AUTOMAKE was being used was causing this warning:

AM_INIT_AUTOMAKE: two- and three-arguments forms are deprecated.  For more info, see:
configure.ac:3: http://www.gnu.org/software/automake/manual/automake.html#Modernize-AM_005fINIT_005fAUTOMAKE-invocation

We now then use AC_INIT and AM_INIT_AUTOMAKE the RightWay(TM).
blam.csproj: update, to include configure.ac instead of configure.in

Sync with the change in e19655638098a15bd82ac586371fd3f3c25f165e
Update gconf-sharp reference to 2.24

Which currently ships with Debian
autogen.sh: set DIE=0 initially

A typo had made us set IE=0. This fixes the other side of
487f217366e4.
configure.ac: use mcs if available
build: use automake to replace the constants in Define.cs

This is preferrable to a sed script, and lets distcheck get further.
Get rid of more GLib.Timeout uses

The runtime provides better ways of doing timers and delays than going
over to glib.
ItemStore: create the XML reader from XmlReader.Create()

Doing new XmlTextReader() won't throw an exception if the file doesn't
exist.