Search UI
Merge branch 'master' into feature/search

Conflicts:
	src/CMakeLists.txt
	src/engine/imap-db/outbox/smtp-outbox-folder.vala

I applied the changes from master in smtp-outbox-folder.vala to
geary-abstract-local-folder.vala in the search branch.
Basic search table implementation; fix #6766

This is a limited implementation, so please backup your database before
running this search feature branch from now on as we may change things.

It's using a Unicode Snowball stemming tokenizer available from
https://github.com/littlesavage/sqlite3-unicodesn, also handily
available in src/sqlite3-unicodesn in Geary.  If you want to look at the
search tables on the command line, cd into the unicodesn source folder,
run make and make install, then load sqlite3 like:

   sqlite3 -cmd '.load unicodesn.sqlext' /path/to/geary.db
Closes #6767 GearySearchFolder type
Hook search folder to full text search
Merge branch 'master' into feature/search
Update email body normalization; fix #6837

This adds a basic, imperfect HTML -> text algorithm using libxml2.  We
use this to turn HTML email bodies into a searchable text corpus.
Basic search query massager; fix #6838

The idea is to have one query syntax that Geary respects, and be able to
use it in SQLite, over IMAP, etc.  This is the SQLite version that
translates what's in the search bar into a more permissive search
against the local database.
Closes #6979 Makes SearchFolder and ConversationMonitor play nice
Background search table population; fix #6984
Choose language-specific search stemmer; fix #6957

We use the list of preferred languages for the user at the time of
search table creation to pick the most relevant stemming algorithm for
our search tokenizer.  If we don't find a stemmer that matches any
preferred language, we use the English stemming algorithm as the
default.
Update sqlite3-unicodesn to latest, 4155579
Split up merging in search table; fix #6957
Update conversations only when all messages have been loaded: Closes #7016
Closes #7015 Folder.CountChangedReason now has append and inserted
Closes #7014 SearchFolder sorted by internaldate
Closes #7031 Searches can now be cancelled
Closes #6963 Search upgrade progress bar
Merge branch 'master' into feature/search
Fix spurious warning when creating toolbar

It looks like when Glade saved the toolbar.glade file recently, it
overwrote some apparently-necessary defaults.  The end result was that
one of our helpers was crashing because the gear menu button was getting
a null label.  If we explicitly set the label in the action, it seems to
make it happy.  This is preferably to undoing the change in the .glade
file because if we did that, the next time someone saved it, it'd just
break again.