conversation: add the ability to remove a conversation from the list

+ Now, the "Delete this conversation" is renamed and clear the history
+ "Remove conversation" now remove the conversation from the list
+ Note: fix some typos

Change-Id: I8873a0db87f416d3ed56d6495a2547da828b94e6
Gitlab: #511
diff --git a/ring-android/app/src/main/res/values/strings.xml b/ring-android/app/src/main/res/values/strings.xml
index 7b3e1bd..b17a2f9 100644
--- a/ring-android/app/src/main/res/values/strings.xml
+++ b/ring-android/app/src/main/res/values/strings.xml
@@ -129,7 +129,7 @@
     <string name="action_call_decline">Decline</string>
     <string name="ab_action_speakerphone">Enable speaker</string>
     <string name="ab_action_contact_add">Add to contacts</string>
-    <string name="ab_action_contact_add_question">Add to contacts ?</string>
+    <string name="ab_action_contact_add_question">Add to contacts?</string>
     <string name="hist_contact_added">Contact added</string>
     <string name="hist_invitation_received">Invitation received</string>
     <string name="ab_action_audio_call">Audio call</string>
@@ -166,22 +166,28 @@
     <string name="scan_qr_account_message">Scan the QR Code of the account you want to add.</string>
 
     <!-- Settings -->
-    <string name="clear_history_dialog_title">Clear history ?</string>
-    <string name="clear_history_dialog_message">This action can not be undone.</string>
+    <string name="clear_history_dialog_title">Clear history?</string>
+    <string name="clear_history_dialog_message">This action cannot be undone.</string>
     <string name="clear_history_completed">History has been cleared.</string>
 
     <!-- Conversation -->
     <string name="conversation_action_delete_this">Delete this conversation</string>
     <string name="conversation_action_delete_this_title">Delete this conversation ?</string>
     <string name="conversation_action_delete_this_message">This action can not be undone.</string>
+    <string name="conversation_action_history_clear">Clear history</string>
+    <string name="conversation_action_history_clear_title">Clear the conversation history?</string>
+    <string name="conversation_action_history_clear_message">This will definitely clear the conversation history.</string>
+    <string name="conversation_action_remove_this">Delete contact</string>
+    <string name="conversation_action_remove_this_title">Delete this contact?</string>
+    <string name="conversation_action_remove_this_message">This will delete the contact and definitely clear the conversation history.</string>
     <string name="conversation_action_copy_peer_number">Copy number</string>
     <string name="conversation_action_copied_peer_number_clipboard">%1$s copied to clipboard</string>
     <string name="conversation_action_select_peer_number">Select a number</string>
-    <string name="conversation_action_block_this">Block this contact</string>
+    <string name="conversation_action_block_this">Block contact</string>
     <string name="conversation_action_go_to_call">Return to ongoing call</string>
 
     <!-- Contacts -->
-    <string name="add_call_contact_number_to_contacts">Add %1$s ?</string>
+    <string name="add_call_contact_number_to_contacts">Add %1$s?</string>
     <string name="prompt_new_password">New password</string>
     <string name="prompt_new_password_optional">New password (optional)</string>
     <string name="prompt_new_password_repeat">Repeat new password</string>