core: Add DIAGE capability to X_DLNADOC

Add DIAGE capability to X_DLNADOC if one is not added already.
core: Add +LPE+ feature to proper X_DLNADOC node

Add capability to enable LPE feature in device xml

Conflicts:
	src/librygel-core/rygel-description-file.vala
	src/librygel-core/rygel-plugin.vala
core: Style fixes

Signed-off-by: Jens Georg <mail@jensge.org>
core: Refactor XPath use

Introduce apply_xpath function and replace four uses of XPath with it.

Also fixed memory leak of not deleting the returned XPath object.

Signed-off-by: Jens Georg <mail@jensge.org>
core: Use early exit pattern

Reduce indentation level by leaving the function as early as possible.

Signed-off-by: Jens Georg <mail@jensge.org>
core: Fix use of OCM flag

Signed-off-by: Jens Georg <mail@jensge.org>
server: Move code for Samsung subtitles

Move it to Samsung hacks class.

Signed-off-by: Jens Georg <mail@jensge.org>
i18n: Exclude doc directory

Signed-off-by: Jens Georg <mail@jensge.org>