Use NuGet for external assembly managements

Remove lib/ directory and relocate external assemblies, start to use NuGet and
install packages, for external assembly management.
Add YacqSilverlight project

Add YacqSilverlight project, a Silverlight library (assembly name Yacq), which
is shared all source codes with Yacq.
Modify source codes to support Silverlight environment.
Add NuGet nuspec file, publish Yacq and YacqSilverlight libraries.
Add YacqSilverlightRun project

Add YacqSilverlightRun, a code pad for Silverlight environment.
Add type imports, Modify GetDescendants, make YacqSilverlightRun's output async

Add type imports in SymbolTable.Root.
Modify implementation of Expression.GetDescendants() extension method for
Silverlight, which is reduced private member accesses.
Make output and some operations asynchronous in YacqSilverlightRun.
Modify CodeCollection not to hit cache and remove dependency of host

Modify CodeCollection in YacqSilverlightRun, add UNIX time query string, not o
hit cache (hack), and use Application.Current.Host.Source.AbsoluteUri property
to remove dependency of deployed host address.
Add symbols, implement variables support (new (let)), fix a bug about invoking

Add symbol aliasing feature (new Add overloads) in SymbolTable.
Modify AmbiguousLambdaExpression, accept plural body expressions (it generates
Block node as the body of lambda).
Add and modify symbols, (printn): Console.Write, (let): creates block use
variables, and modify its notation, ($): an alias of (let), (fun): former (\)
and (\) is now alias of (fun).
Fix a bug in ListExpression.ReduceImpl(), reduces Invoke node for all invokable
nodes (delegates and lambda expressions).
Improve error handling

Add ParseException, a common exception class in parsing, and it also provides
Token property which the error occurs optionally.
Modify codes to report correct errors.
Modify the implementation of (apply), fix bugs

Modify the implementation and the usage of (apply) symbol; the new usage is
same as (let) and (fun).
Fix a bug in YacqRun, ignore empty input.
Fix (or improve) the string format for SymbolEntry whose LeftType is Static<>.
Split SymbolEntry and SymbolDefinition types from SymbolTable.cs.
Change the patterns for string literals, Add history feature in YacqRun

Change the patterns for string literals in Tokenizer.
Add history (of reduced expressions) features in YacqRun, this adds special
symbols only in YacqRun, !C, !E, !R, and !H.
Implement escape sequences and code-embedding in string literals

Implement features in TextExpression, escape sequences and code embedded
strings (this generates String.Format method call).
Write document comment of ParseException with a little hack.
Implement inner-embedded-code escaping

Add escaping code for inner-embedded-codes in TextExpression.
Remove useless debug code.
Support plural expressions for Object macro methods

Support plural expressions (generates Block) for arguments of Object.(let) and
Object.(apply) macro methods.
Add query operator methods for IQueryable<> (and IEnumerable<>), fix a bug

Add query operator (not only standard query operators, but also in Ix) methods
as members of YacqQueryable<T> class, it can create by Yacq() extension method
in YacqServices, for IQueryable<T> and IEnumerable<T> (called AsQueryable()).
Adding query operators for IQbservable<> and IObservable<> is started:
YacqQbservable<T> class is created, but methods are not implemented just now.
Also, query operators for non-generic methods is planned and fundamental
class is created but only in plan just now, too.
Fix a bug in ListExpression, correct to fit the calling rules.
Add a NuGet package

Add MvvmLightLibs package from NuGet and replace assembly references outside
the repository.
Add document comments, fix bugs

Add missing document comments.
Fix a bug in YacqServices and YacqQbservable, Symbols is missed.
Fix a bug in YacqQueryable, calling method mistake.
Add methods in YacqQbservable, reorder YacqQueryable methods, write documents

Add query operator methods and its document comments in YacqQbservable.
Reorder query operator methods in YacqQueryable and fix document comments.
Support abbreviated form in YacqServices.ParseLambda methods

Support to omit the most outer parentheses (list tokens ( ), not [ ] and { }),
only in YacqServices.ParseLambda methods and the expression in specified code
is not only one.
Add a escape sequence (\s), add query operators in YacqQbservable

Add a espace sequence '\s', represents a ASCII space ' '.
Add query operators in YacqQbservable, Subscribe methods (they can't be passed
Expression<>, so codes must be compiled).
Change the select of some overloads in query operators

Change the rule to sort out some overloads in query operators, because of its
parameter type (see: http://twitter.com/neuecc/status/121538248551038976).
Replace to new nuspec file

Replace the nuspec file.
Change whole versions: 1.0 to 1.5.