0.2.0

• enh: mutable accessors
• enh: no-cache with more control tags + pragma
• fix: no-cache reset if not used
• enh: more tests added
• enh: cache control tags sorted by name
• enh: lowercased header names
• fix: CacheHeaderBuilder::reset() staleWhileRevalidate and staleIfError
• enh: header always converted to lowercase
• enh: CacheHeaderBuilder::hasLastModified(), hasEtag(), isNoCache(), isEmpty(), isNotEmpty(), getEtag()
• remove: ModifiedMatcherResult:: isBeforeModifiedSince, isAfterModifiedSince, isBeforeModifiedAt, isAfterModifiedAt,
  isEqualsModifiedAt, isEqualsUnmodifiedSince
• enh: ModifiedMatcherResult::isModifiedSince, matchesModifiedAt, isUnmodifiedSince
• fix: empty ETAG use as NO ETAG