Add a `title` write argument to `getContent*` methods.
This argument is filled with the title of the content get.
Also update the JNI accordingly.
Related to kiwix/kiwix-android#214
libzim only know how to read embedded full text index in a zim file.
This is nice as we want to embedded the full text index in zim file and
not have separated full text index.
However, we still have some zim+separated index we have to read.
So we have to support the search in separated index for a while.
`kiwix-android` is using `kiwix-lib` as an external java application now.
So we need `kiwix-lib` build system to also install application files
(manifest, resources, ..).
The commit 83d2725 adapt the jni wrapper to the new search API but try to
use the `Result` class from the `kiwix` namespace but `Result` is not in
the namespace.
A correct fix would be to move `Result` in `kiwix` but it also change the
API for other tools (kiwix-tools). As we will move the search
functionality in `zimlib` it is better to just do this silly fix and
update the API latter when moving the search functionality.
We don't need to generate a vector of result when we do a search.
We better to just keep the handle to the current MSetIterator and
generate the wanted values when needed.
Matthieu Gautier
kelson42