[thrift] gut Erlang exception handling

Summary: * move type field to tException from subclasses
          * add backtrace to tException
          * add oop:is_a
          * on exit, wrap exceptions in {thrift_exception, E} ... otherwise can't distinguish e.g. exit:{{tBinProtException, {tException, ...}}, Stack} vs. exit:{tBinProtException, {tException, ...} -- I hate erlang
          * all throws/exits to tException:throw which does the wrapping described above

Reviewed By: eletuchy

Test Plan: been using this code on my live server ^_^

Revert: OK


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665350 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/erl/src/protocol/tBinaryProtocol.erl b/lib/erl/src/protocol/tBinaryProtocol.erl
index 207f305..efcfd77 100644
--- a/lib/erl/src/protocol/tBinaryProtocol.erl
+++ b/lib/erl/src/protocol/tBinaryProtocol.erl
@@ -136,14 +136,13 @@
     ?L1(writeI32, length(Str)),
     ?R1(Trans, effectful_write, Str).
 
-%
+%%
 
 readMessageBegin(This) ->
     Version = ?L0(readI32),
     if
         (Version band ?VERSION_MASK) /= ?VERSION_1 ->
-            throw(tProtocolException:new(?tProtocolException_BAD_VERSION,
-                                         "Missing version identifier"));
+            tException:throw(tProtocolException, [?tProtocolException_BAD_VERSION, "Missing version identifier"]);
         true -> ok
     end,
     Type = Version band 16#000000ff,
@@ -177,7 +176,7 @@
     Size  = ?L0(readI32),
     { Etype, Size }.
 
-%
+%%
 
 readBool(This) ->
     Byte = ?L0(readByte),