Allow using return value from passthrough/1

Fixes issue #2.
Add changelog item about passthrough/1 change
Change internal data representation

Internal data representatin needs to be changed to allow support for
hamcrest argument matchers and argument dependent sequences and loops.

Extend expect syntax to allow Arg patterns

The syntax of expect function was extended to allow defining
expectition through a list of Arg patterns like ['_', 1, blah]
and define results as any of sequence, loop, or value.

Fix merge mistake
Address code inspection comments

Exports one per line;
Corrected when clauses;
Code kept to 80 chars per line;
One liners formatted to one line.
Deprecate sequence/4 and loop/4

Deprecate obsolete functions to encourage usage of the
new API, that is expect/3,4 + seq/1,loop/1,/val/1.
Move match spec compilation to the caller

Match specification compilation was moved to the calling
process to be make matching more time efficient.
Raise function_clause in case of missing args pattern
Make sequence/4 and loop/4 use the unified expect backend
Throw invalid_arity if multi-clause expectation is not valid
Address the second round of code inspection comments
Add unit test covering invalid expect call
Merge pull request #73 from horkhe/feature/args-filter

Extended expect syntax and more
Introduce exceptions in sequences
Small fix in ret_spec() definition
Merge pull request #74 from horkhe/feature/new-exception-syntax

New exception syntax
Fix line width issues

All line widths should stay under 80 characters.
Add missing comma
Add spawn_opt option for new

Typically used to specify non-default, garbage collection options.
Add no_history option for new
Merge pull request #77 from norton/norton-develop

Two new options for meck