Server-side named parameters validation is too restrictive about "~", ".", "-" chars

[medvedev]

Hi, As for RFC3986, section 2.3, characters "~", ".", "-" are legal besides alphanumeric chars and underscore. Current server-side validation for named parameters (that may be "path" or "query params" URL part) allows alphanumeric chars and underscore only. Here's reference to corresponding code: com.google.api.server.spi.dispatcher.PathTrie: private static final Pattern PARAMETER_NAME_PATTERN = Pattern.compile("[a-zA-Z_][a-zA-Z_\\d]*");