Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=57281
Use interfaces rather than implementations to call Filter and Servlet
methods when running under a security manager.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1643283 13f79535-47bb-0310-9956-ffa450edef68
Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=57308
Avoid unnecessary use of System.getProperty("file.separator")
Format
Part 1 of fix for
https://issues.apache.org/bugzilla/show_bug.cgi?id=57309
Addressed the direct calls to ELSupport.coerceToType()
Still need to address the type specific versions of that method.
Part 2 of fix for
https://issues.apache.org/bugzilla/show_bug.cgi?id=57309
Run all the type specific conversions through the ELResolver
Add a test case for
https://issues.apache.org/bugzilla/show_bug.cgi?id=57284
Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=57284
Enable startAsync() to be called from a Filter and still be able to call
the remainder of the FilterChain