ctor specialization

[advasileva]

Now speco should be able to specialize the simplest case of attribute polymorphism (construction) as in the core issue.
This consists of

1. Сreating specialized versions of objects (in the <objects/> tag), e.g. adding a:

[x] > foo1
  x.boom > @
[x] > foo2
  x.boom > @

2. Replacing the call in the application line, e.g.:

from

foo first
foo second

to

foo1 first
foo2 second

[0pdd]

@advasileva the puzzle #28 is still not solved.

[0pdd]

@advasileva the only puzzle #28 is solved here.