[geary] Don't (expicitly) use deprecated Gee methods.

[Michael Gratton <mjog src gnome org>]

commit 1cb8b77b486edfc3bbc8998fd493cdd5d0c6cbc4
Author: Michael James Gratton <mike vee net>
Date:   Sat Mar 4 10:23:20 2017 +1100

    Don't (expicitly) use deprecated Gee methods.

 .../conversation-list/conversation-list-store.vala |    2 +-
 .../conversation-viewer/conversation-list-box.vala |    2 +-
 .../conversation-viewer/conversation-message.vala  |    2 +-
 src/engine/rfc822/rfc822-message.vala              |    2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/src/client/conversation-list/conversation-list-store.vala 
b/src/client/conversation-list/conversation-list-store.vala
index 81e2fdb..c3fc1dd 100644
--- a/src/client/conversation-list/conversation-list-store.vala
+++ b/src/client/conversation-list/conversation-list-store.vala
@@ -389,7 +389,7 @@ public class ConversationListStore : Gtk.ListStore {
             remove(iter);
 #endif
         
-        row_map.remove(conversation);
+        row_map.unset(conversation);
     }
     
     private bool add_conversation(Geary.App.Conversation conversation) {
diff --git a/src/client/conversation-viewer/conversation-list-box.vala 
b/src/client/conversation-viewer/conversation-list-box.vala
index 30a59c1..46ea1a6 100644
--- a/src/client/conversation-viewer/conversation-list-box.vala
+++ b/src/client/conversation-viewer/conversation-list-box.vala
@@ -485,7 +485,7 @@ public class ConversationListBox : Gtk.ListBox {
             if (this.cancellable.is_cancelled()) {
                 break;
             }
-            if (!this.email_rows.contains(full_email.id)) {
+            if (!(full_email.id in this.email_rows)) {
                 EmailRow row = add_email(full_email);
                 if (row.is_expanded &&
                     (first_expanded_row == null ||
diff --git a/src/client/conversation-viewer/conversation-message.vala 
b/src/client/conversation-viewer/conversation-message.vala
index d4be5e6..036ba09 100644
--- a/src/client/conversation-viewer/conversation-message.vala
+++ b/src/client/conversation-viewer/conversation-message.vala
@@ -101,7 +101,7 @@ public class ConversationMessage : Gtk.Grid {
         }
 
         public bool highlight_search_term(string term) {
-            bool found = this.search_value.contains(term);
+            bool found = term in this.search_value;
             if (found) {
                 get_style_context().add_class(MATCH_CLASS);
             } else {
diff --git a/src/engine/rfc822/rfc822-message.vala b/src/engine/rfc822/rfc822-message.vala
index 9dd2565..a2e2868 100644
--- a/src/engine/rfc822/rfc822-message.vala
+++ b/src/engine/rfc822/rfc822-message.vala
@@ -198,7 +198,7 @@ public class Geary.RFC822.Message : BaseObject {
                     }
                     // Don't need to assign a CID to this file, so
                     // don't process it below any further.
-                    inline_files.remove(cid);
+                    inline_files.unset(cid);
                 }
             }