Don't include internal/private symbols in Engine VAPI

Removing internal and private symbols from geary-static.vapi results
in removing 1,000 lines from the file.  Although testing doesn't show
an appreciable increase in compile time (w/ make -j8 on my 8-core
machine), by reducing symbol leakage partial builds should improve.

This patch also fixes a couple of symbols marked internal but being
used publicly (and necessarily so) and a couple of errordomains in
the Engine not placed in the Geary namespace.

cmake/ValaPrecompile.cmake

@@ -170,7 +170,7 @@ macro(vala_precompile output source_bundle_name)
     set(vapi_arguments "")
     if(ARGS_GENERATE_VAPI)
         list(APPEND out_files "${DIRECTORY}/${ARGS_GENERATE_VAPI}.vapi")
-        set(vapi_arguments "--internal-vapi=${ARGS_GENERATE_VAPI}.vapi")
+        set(vapi_arguments "--vapi=${ARGS_GENERATE_VAPI}.vapi")
         
         # Header and internal header is needed to generate internal vapi
         if(NOT ARGS_GENERATE_HEADER)

src/engine/api/geary-account-information.vala

@@ -52,7 +52,12 @@ public class Geary.AccountInformation : BaseObject {
     
     private static Gee.HashMap<string, Geary.Endpoint>? known_endpoints = null;
     
-    internal File? settings_dir = null;
+    /**
+     * Location account information is stored (as well as other data, including database and
+     * attachment files.
+     */
+    public File? settings_dir { get; private set; default = null; }
+    
     internal File? file = null;
     
     // IMPORTANT: When adding new properties, be sure to add them to the copy method.

src/engine/api/geary-search-folder.vala

@@ -4,7 +4,7 @@
  * (version 2.1 or later).  See the COPYING file in this distribution.
  */
 
-public class Geary.SearchFolderRoot : Geary.FolderRoot {
+private class Geary.SearchFolderRoot : Geary.FolderRoot {
     public const string MAGIC_BASENAME = "$GearySearchFolder$";
     
     public SearchFolderRoot() {
@@ -12,7 +12,7 @@ public class Geary.SearchFolderRoot : Geary.FolderRoot {
     }
 }
 
-public class Geary.SearchFolderProperties : Geary.FolderProperties {
+private class Geary.SearchFolderProperties : Geary.FolderProperties {
     public SearchFolderProperties(int total, int unread) {
         base(total, unread, Trillian.FALSE, Trillian.FALSE, Trillian.TRUE, true, true, false);
     }

src/engine/imap-engine/gmail/imap-engine-gmail-search-folder.vala

@@ -7,7 +7,7 @@
 /**
  * Gmail-specific SearchFolder implementation.
  */
-public class Geary.ImapEngine.GmailSearchFolder : Geary.SearchFolder {
+private class Geary.ImapEngine.GmailSearchFolder : Geary.SearchFolder {
     private Geary.App.EmailStore email_store;
     
     public GmailSearchFolder(Geary.Account account) {

src/engine/mime/mime-error.vala

@@ -8,6 +8,6 @@
  * Errors related to {@link Geary.Mime}.
  */
 
-public errordomain MimeError {
+public errordomain Geary.MimeError {
     PARSE
 }

src/engine/nonblocking/nonblocking-error.vala

@@ -4,7 +4,7 @@
  * (version 2.1 or later).  See the COPYING file in this distribution.
  */
 
-public errordomain NonblockingError {
+public errordomain Geary.NonblockingError {
     /**
      * Indicates a call was made when it shouldn't have been; that the primitive was in such a
      * state that it cannot properly respond or account for the requested change.

src/engine/rfc822/rfc822.vala

@@ -10,7 +10,7 @@ private int init_count = 0;
 
 internal Regex? invalid_filename_character_re = null;
 
-internal void init() {
+public void init() {
     if (init_count++ != 0)
         return;