1. Get the subset of books matching the q (title/description) parameter
of the search
2. Filter out books not matching the other parameters of the search.
Stage 1. currently works in the old way, but will be replaced by Xapian
based search in subsequent commits.
The default value of this parameter is false, in this case all the bookmarks
are returned, otherwise only those who are related to books of the library.
Instead of having a single method `listBooksIds` that tries to be
exhaustive about all the filter and sort option, split the method in
two separated methods `filter` and `sort`.
The `filter` method takes a `Filter` object that represent on what we are
filtering. This object has to be construct before calling `filter`.
```cpp
Filter filter;
filter.query("Astring");
filter.acceptTags({"nopic"});
// return all book in eng and with "Astring" in the tile or description".
library.filter(filter);
//equivalent to
library.listBooksIds(ALL, UNSORTED, "Astring", "", "", "", {"nopic"});
// or better
library.filter(Filter().query("Astring").acceptTags({"nopic"}));
```
The method `listBooksIds` has been marked as deprecated.
Add a small test on the library.
The library now contains (simple) methods to handle bookmarks.
The bookmark are stored in a separate xml file.
Bookmark are mainly a couple (`zimId`, `articleUrl`).
However, in the xml we store a bit more data :
- The article's title (for display)
- The book's title, lang and date (for potential update of zim files)
It is up to the book to manage its attribute.
Also remove the `absolutePath` (and `indexAbsolutePath`). The `Book::path` is always stored
absolute.
The fact that the path can be stored absolute or relative in the
`library.xml` is not relevant for the book.
There is no more integrated build of dependencies in the build system.
Dependencies are discovered using pkg-config except for ctpp2 where there
is no pkg-config file.