get away from argument stringlists. instead, use native shell command
lines which support quoting/splitting, environment variable expansion
and redirections with well-understood semantics.

Task-number: QTCREATORBUG-542
Task-number: QTCREATORBUG-1564

this is a wrapper around QProcess with these features:
- setEnvironment() takes a Utils::Environment instead of a QStringList
- instead of taking a stringlist with arguments, take a single shell
  command string which is fully compatible with the system's native
  shell (the bourne shell on unix and cmd.exe on windows) - with support
  for environment variable expansion, and subject to the shell's
  splitting and quoting rules. if the command is too complex (e.g.,
  contains redirections), it is transparently executed through a real
  shell.
- additionally, the class contains a set of helper functions for
  manipulating (constructing, splitting, etc.) shell command lines.
  in particular, it contains a shell-safe macro expander and the nested
  class ArgIterator which can be used for inspecting and manipulating a
  shell command line without going through the stringlist indirection
  (which is potentially lossy).

some of this is based on KDE code (KShell and KMacroExpander) which i
have written myself.

AbstractMacroExpander (any macros), AbstractQtcMacroExpander (%{var}
style macros, which is a hybrid of printf format specifiers and unix
environment expansions) and expandMacros() for the actual string
manipulation.

instead of being os-agnostic, interpret the os-native expansion style,
so it is consistent with proper (shell) command lines.

don't interpret quotes, as this function is meant for expanding isolated
filepaths, where nobody would expect quoting. instead, use the windows
style of simply not doing an expansion if a referenced variable is not
found, which should be good enough - it's rather unlikely that something
which happens to be an expansion of an existing variable is actually not
meant to be one.

Reviewed-by: Erik Verbruggen

Task-number: QTBUG-15170

Reviewed by:  hjk

They are unusable on linux as there are commonly-included macros
of the same name.

Reviewed-by: Roberto Raggi

Task-number: QTCREATORBUG-2642
Reviewed-by: Erik Verbruggen

This will allow distinguishing mere strings from urls and allow
different completion.

Reviewed-by: Erik Verbruggen

Reviewed-by: Erik Verbruggen

Eventually we will need some way to locate an identifier's
definition, so add "lineno" to each AST node.  May want to
change this to "position" later.  The makeAstNode<T>() function
takes care of automatically decorating nodes with line numbers.

We have to follow the prototype chain

Reviewed-by: Christian Kamm

Reviewed-by: Christian Kamm

Added
hasLocalProperty()
hasProperty()
keysForEnum()

Reviewed-by: Christian Kamm

This allows to distinguish between int an real numbers

Reviewed-by: Christian Kamm

Reviewed-by: Christian Kamm

Done-with: Christian Kamm

Reviewed-by: Thomas Hartmann