Added option in FLAIM to disable direct I/O on Linux and Unix platforms. Re-architected the FTK I/O layer and cleaned up the async interfaces.

git-svn-id: https://svn.code.sf.net/p/flaim/code/trunk@643 0109f412-320b-0410-ab79-c3e0c5ffbbe6

flaim/src/fsconvrt.cpp

@@ -100,7 +100,7 @@ RCODE FSVersionConversion40(
 			// VISIT: the change may not be necessary - may be new version.
 			// Look at the root block type.
 			
-			if( pStack != stackBuf) // &&  ? Need to look at real block type?
+			if( pStack != stackBuf)
 			{
 				DbConvertInfo.uiContainer = pLFile->uiLfNum;