refactor: rename PIP_NO_\* to PIP_HAS_\* with inverted logic

All feature flags now use positive naming (enabled by default):
- PIP_HAS_FILESYSTEM, PIP_HAS_THREADS, PIP_HAS_SOCKET
- PIP_HAS_PROCESS, PIP_HAS_DYNLIB, PIP_HAS_FFT, PIP_HAS_SERIAL

Preprocessor guards inverted:
- #ifndef PIP_NO_X → #ifdef PIP_HAS_X
- #ifdef PIP_NO_X → #ifndef PIP_HAS_X

CMake options default ON instead of OFF.
Platform blocks set flags OFF to disable features.

85 files transformed via Python script + 2 manual fixes.

libs/main/thread/pithread.cpp

@@ -17,7 +17,7 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef PIP_NO_THREADS
+#ifdef PIP_HAS_THREADS
 #  include "pithread.h"
 
 #  include "piincludes_p.h"
@@ -450,7 +450,7 @@ __THREAD_FUNC_RET__ thread_function_once(void * t) {
 //! \return \c false если таймаут истёк
 
 
-#  ifndef PIP_NO_THREADS
+#  ifdef PIP_HAS_THREADS
 
 __PIThreadCollection * __PIThreadCollection::instance() {
 	return __PIThreadCollection_Initializer__::__instance__;
@@ -516,7 +516,7 @@ __PIThreadCollection_Initializer__::~__PIThreadCollection_Initializer__() {
 	}
 }
 
-#  endif // PIP_NO_THREADS
+#  endif // PIP_HAS_THREADS
 
 
 PRIVATE_DEFINITION_START(PIThread)
@@ -1003,7 +1003,7 @@ void PIThread::runOnce(PIObject * object, const char * handler, const PIString &
 		delete t;
 		return;
 	}
-#  ifndef PIP_NO_THREADS
+#  ifdef PIP_HAS_THREADS
 	__PIThreadCollection::instance()->startedAuto(t);
 	CONNECT0(void, t, stopped, __PIThreadCollection::instance(), stoppedAuto);
 #  endif
@@ -1037,7 +1037,7 @@ void PIThread::runOnce(std::function<void()> func, const PIString & name) {
 	PIThread * t = new PIThread();
 	t->setName(name);
 	t->setSlot(std::move(func));
-#  ifndef PIP_NO_THREADS
+#  ifdef PIP_HAS_THREADS
 	__PIThreadCollection::instance()->startedAuto(t);
 	CONNECT0(void, t, stopped, __PIThreadCollection::instance(), stoppedAuto);
 #  endif
@@ -1079,4 +1079,4 @@ bool PIThread::_waitForFinish(PISystemTime max_tm) {
 #  endif
 	return false;
 }
-#endif // PIP_NO_THREADS
+#endif // PIP_HAS_THREADS