moved all switches to syntax module

"context restriction not allowed for fully polymorph instance" and
"context restriction equals instance type"

dcl macros in icl functions and macros
removed expanded macros from groups (s.c.components)

"first argument of infix operator missing" and
"second argument of infix operator missing"

 (changes are commented with "MW0")

before:
  _from_to undefined
  _uselect undefined
now:
  StdEnum not imported
  StdArray not imported

of "v314", case defaults and guards now also have file position information.

algorihm so that typing error messages can indicate the alternative in
which the error occured. Before, these error messages always located the
first alternative/function type

nieuwe PD_coerce-symbool werd nog niet aangepast.

  #! x = y

will be transformed into

  #! x = _dummyForStrictAlias y

while checking. The new predefined symbol _dummyForStrictAlias has
the type of the identity function. This application will be removed
in the backend conversion phase. In this case x and y will simply get
the same sequence number (see module backendpreprocess). Then the
binding can be ignored.

:: T :== Int

f = { T | f1 = blub }

really redundant, but not those which are added automatically by the compiler
to the icl module

 #! (a, b) = f

was originally translated into

 #! _x = f
 #! a = _x.0
 #! b = _x.1

which is wrong. Now a an b are in a lazy context

   in "convertCasesOfFunctionsIntoPatterns" and "collectVariables")
 - new switch "SwitchUniquenessBug" in module checksupport
 - several bugfixes

bugfix

    (new module: comparedefimp)
- implemented array patterns. Further work: arrays are in lazy context (should be strict),
    currently only one dimensional arrays
- optimised memory usage for explicit imports

trans.icl: improving sjaaks changes that yielded revision 1.17
parse.icl: bugfix: The following program led into "could not determine the type of this record"

module t5

:: R1 = { f :: Int }
:: R2 = { f :: Int }
:: R3 = { g :: R1 }

g x = { x & g.R1.f = 1 }

    Check Error [case_bug.icl,18,f]:"_" illegal combination of patterns
    f t = case t of {(a,2) -> 1;	_ | False -> 2;	(a,b) -> 3;};
- typesupport.icl: small typo
- trans.icl: small optimisation