Symbian-abld and symbian-sbsv2 mkspecs replace characters with underscore in TARGET too aggressively

"-" and "." characters in TARGET variable should not be replaced by underscores, as these are acceptable characters in a Symbian binary name (at least toolchain allows them no problem when manually given in MMP target). The reason why this replacement is done is because the fixed target name is used in many constructs in various generated files, and in some of those constructs these characters are not allowable. However, there is no compelling reason to use the exact same string for all these constructs as long as they can all be predictably derived from TARGET.

Doing this replacement makes binaries produced by symbian-abld and symbian-sbsv2 mkspecs to be different than those produced by Makefile based mkspecs, which is very bad e.g. for any project that wants to link against a library that has one of these replaced characters in its name.

Note that changing this behavior may cause regressions in some projects that have these characters in TARGET in .pro file.