removing unused .class files
adding .class to .gitignore
Merge pull request #2 from qmx/cleanup

Cleanups (.class files)
Use heading instead of trailing arguments for the language runtime specific context arguments.
Add convenience compose() & hasBeenInvalidated() methods to GuardedInvocation.

These methods allow RelinkableCallSite implementations to have more concise
code by relying on these methods.
Pass "relink" as argument to setGuardedInvocation, don't put it in call site.

"relink" is now being passed as an argument to setGuardedInvocation instead of
being put as a field in the RelinkableCallSite. This allows the call sites to
remain smaller at the expense of recreating the relink method more frequently.

Also, got rid of the callSiteDescriptor argument in relinkAndInvoke() as it
can be extracted from callSite, making the relink method handles slimmer.
Added syncOnRelink property to DynamicLinkerFactory.

Dynamic linkers created with syncOnRelink=true will invoke 
MutableCallSite.syncAll for a call site whenever they relink it. Defaults to
false, but is encouraged to be set to true when used by language runtimes that
support multithreaded execution.
New call site type, the chained call site.

It maintains a chain of linked method handles (up to at most 8 in the default
implementation) cascading from one to the other through guardWithTest(). 
Switchpoint-invalidated elements in the chain are removed eagerly.
Get rid of the setRelink() method; since we aren't storing relink anymore, we 
can just use the setTarget(). Unfortunately, we can no longer guard against it
being set more than once, but it shouldn't be much of an issue, as these call
sites are ordinarily not visible outside of the linker.
Mention ChainedCallSite in RelinkableCallSite documentation.
Be explicit about interning the operation strings
The ordering of arguments is now (this[, contextArgs], normalArgs).

"this" always comes first, followed by context arguments, if any, followed by
normal arguments.
Add a Travis config file - note, this will not work until we can specify Java 7.
Added an isNull() guard.
Typo fix
- Allow dyn:new to operate on ClassStatics
- Expose "class" synthetic property on ClassStatics
Added a convenience vararg method for adding fallback linkers.
- CallSiteDescriptor is now an interface (used to be pure abstract class).
- Removed support for conveying additional bootstrap arguments in 
  CallSiteDescriptor. These are always implementation specific (ordered 
  sequence of compile-time constants) and as such not usable between language
  runtimes. Individual language runtimes can create specific implementations
  of CallSiteDescriptor with additional information and check for it; it 
  however doesn't make sense for a generic Dynalink API.
- Added support for canonicalization of "standard" CallSiteDescriptors in the
  CallSiteDescriptorFactory, as we expect lots of them to be repeatedly used,
  i.e. if your code uses variable "x" extensively, there will likely be a lot 
  of call sites that can be described with "dyn:getProp:x(Object)Object" and 
  "dyn:setProp:x(Object, Object)".
- Added space-optimal "UnnamedDynCallSiteDescriptor" and 
  "NamedDynCallSiteDescriptor" classes for representing standard "dyn:*" 
  operations with public lookup.
Class statics should be serializable.
NamedDynCallSiteDescriptor can extend UnnamedDynCallSiteDescriptor.