[~] Performance optimizations around Attachment[] and Launchable[] arrays

AIMNAS with its ~50K elements in Attachment[] suffered of performance drop when MOLLE stuff is in the visible inventory. To resolve it the following is done:
* Introduce gMAXATTACHMENTS_READ with actual number of elements in Attachment[]; according refactoring.
* Introduce gMAXLAUNCHABLES_READ with actual number of elements in Launchable[]; according refactoring.
* Introduce std::multimap AttachmentBackmap for quick access to attachments using itemId as a key.
* Sort Attachment[] by attachmentIndex right after loading from XML. According order in XML is not needed anymore.
* Introduce FindAttachmentRange() for quick access to attachments using attachmentId as a key (binary search in Attachment[]).
In a few words, GetHelpTextForItemInLaptop(), ValidAttachment(), SetAttachmentSlotsFlag() were heavily optimized.

Tactical/XML_Launchable.cpp

@@ -19,6 +19,8 @@ struct
 }
 typedef launchableParseData;
 
+UINT32 gMAXLAUNCHABLES_READ = 0;
+
 static void XMLCALL
 launchableStartElementHandle(void *userData, const XML_Char *name, const XML_Char **atts)
 {
@@ -168,9 +170,9 @@ BOOLEAN ReadInLaunchableStats(STR fileName)
 		return FALSE;
 	}
 
+	gMAXLAUNCHABLES_READ = pData.curIndex + 1;
+
 	MemFree(lpcBuffer);
-
-
 	XML_ParserFree(parser);
 
 	return( TRUE );