Fix some markdown issues in library docs (related to https://github.com/dart-lang/dartdoc/issues/96…

sdk/lib/core/uri.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.core;
 
 /**
  * A parsed URI, such as a URL.
  *
  * **See also:**
@@ skipping 651 matching lines @@
    * Creates a new file URI from an absolute or relative file path.
    *
    * The file path is passed in [path].
    *
    * This path is interpreted using either Windows or non-Windows
    * semantics.
    *
    * With non-Windows semantics the slash ("/") is used to separate
    * path segments.
    *
-   * With Windows semantics, backslash ("\") and forward-slash ("/")
+   * With Windows semantics, backslash ("\\") and forward-slash ("/")
    * are used to separate path segments, except if the path starts
-   * with "\\?\" in which case, only backslash ("\") separates path
+   * with "\\\\?\\" in which case, only backslash ("\\") separates path
    * segments.
    *
    * If the path starts with a path separator an absolute URI is
    * created. Otherwise a relative URI is created. One exception from
    * this rule is that when Windows semantics is used and the path
    * starts with a drive letter followed by a colon (":") and a
    * path separator then an absolute URI is created.
    *
    * The default for whether to use Windows or non-Windows semantics
    * determined from the platform Dart is running on. When running in
@@ skipping 1186 matching lines @@
 
   /**
    * Returns the file path from a file URI.
    *
    * The returned path has either Windows or non-Windows
    * semantics.
    *
    * For non-Windows semantics the slash ("/") is used to separate
    * path segments.
    *
-   * For Windows semantics the backslash ("\") separator is used to
+   * For Windows semantics the backslash ("\\") separator is used to
    * separate path segments.
    *
    * If the URI is absolute the path starts with a path separator
    * unless Windows semantics is used and the first path segment is a
    * drive letter. When Windows semantics is used a host component in
    * the uri in interpreted as a file server and a UNC path is
    * returned.
    *
    * The default for whether to use Windows or non-Windows semantics
    * determined from the platform Dart is running on. When running in
@@ skipping 1460 matching lines @@
   // All non-escape RFC-2396 uric characters.
   //
   //  uric        =  reserved | unreserved | escaped
   //  reserved    =  ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | ","
   //  unreserved  =  alphanum | mark
   //  mark        =  "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
   //
   // This is the same characters as in a URI query (which is URI pchar plus '?')
   static const _uricTable = Uri._queryCharTable;
 }