Summary:
* `NULL` -> `nullptr`
* `gui` -> Function `getGUI()`
* `pluginFactory` -> Function `getPluginFactory()`
* `assert` (redefinition) -> using `NDEBUG` instead, which standard `assert` respects.
* `powf` (C stdlib symbol clash) -> removed and all expansions replaced with calls to `std::pow`.
* `exp10` (nonstandard function symbol clash) -> removed and all expansions replaced with calls to `std::pow`.
* `PATH_DEV_DSP` -> File-scope QString of identical name and value.
* `VST_SNC_SHM_KEY_FILE` -> constexpr char* with identical name and value.
* `MM_ALLOC` and `MM_FREE` -> Functions with identical name and implementation.
* `INVAL`, `OUTVAL`, etc. for automation nodes -> Functions with identical names and implementations.
* BandLimitedWave.h: All integer constant macros replaced with constexpr ints of same name and value.
* `FAST_RAND_MAX` -> constexpr int of same name and value.
* `QSTR_TO_STDSTR` -> Function with identical name and equivalent implementation.
* `CCONST` -> constexpr function template with identical name and implementation.
* `F_OPEN_UTF8` -> Function with identical name and equivalent implementation.
* `LADSPA_PATH_SEPARATOR` -> constexpr char with identical name and value.
* `UI_CTRL_KEY` -> constexpr char* with identical name and value.
* `ALIGN_SIZE` -> Renamed to `LMMS_ALIGN_SIZE` and converted from a macro to a constexpr size_t.
* `JACK_MIDI_BUFFER_MAX` -> constexpr size_t with identical name and value.
* versioninfo.h: `PLATFORM`, `MACHINE` and `COMPILER_VERSION` -> prefixed with `LMMS_BUILDCONF_` and converted from macros to constexpr char* literals.
* Header guard _OSCILLOSCOPE -> renamed to OSCILLOSCOPE_H
* Header guard _TIME_DISPLAY_WIDGET -> renamed to TIME_DISPLAY_WIDGET_H
* C-style typecasts in DrumSynth.cpp have been replaced with `static_cast`.
* constexpr numerical constants are initialized with assignment notation instead of curly brace intializers.
* In portsmf, `Alg_seq::operator[]` will throw an exception instead of returning null if the operator index is out of range.
Additionally, in many places, global constants that were declared as `const T foo = bar;` were changed from const to constexpr, leaving them const and making them potentially evaluable at compile time.
Some macros that only appeared in single source files and were unused in those files have been removed entirely.
The spectural analysis was using a rectangle window, leading to high spectural leakage.
This pull request uses the Blackman-Harris window to give a display more representative of the audio.
* redesign of EQ plugin
* correct some symbols
* set pixelPerUnitHeight to float
* change textcolor of inactive handles to white
* revert changes in styles.css
* change grid color/adjust Fontsize of info box / change analizing color
* range changed (20 - 20000 Hz) / display width increased
* Update the EQ faders and remove unused files
* Increase transparency of the graph
* corrects the filter fader peak
* makes fader peak display more useful
* Implement @zapashcanon's suggestions
* calcuculate curve path only when data has changed
* calculate spectrum analyzer only if signal input
* code clean up / coding conventions
* changes according coding guidelines/performance improvements in spectrum analyser/curves painting
* minor changes/white spaces
* change init order
* connect analyze view to gui->mainWindow()->periodicUpdate()
* consolidate some functions (d.r.y.)
* minor syntax changes
* fixes a right mouse button bug
* correct steepness of flanks in high and low pass filters
* Whitespaces
