Fixed comparisons in ReadString and ReadString to compare against 128 instead of 127.

Author: rstam

Bson/IO/BsonBuffer.cs

@@ -543,10 +543,10 @@ public string ReadString()
 
  // special case single character strings
  case 2:
- var c = _chunk[_chunkOffset];
- if (c < 127)
+ var c1 = _chunk[_chunkOffset];
+ if (c1 < 128)
  {
- value = __asciiStringTable[c];
+ value = __asciiStringTable[c1];
  }
  else
  {
@@ -609,7 +609,7 @@ public string ReadCString()
  if (_chunk[_chunkOffset + 1] == 0)
  {
  string value;
- if (c1 < 127)
+ if (c1 < 128)
  {
  value = __asciiStringTable[c1];
  }