Large refactor of the entire codebase

Saw that layout really should be separated from the style struct, so went ahead and pulled the trigger...
A bunch of other refactors have also been done

* Lifted layout out of style, its not separate in UI_Box and in UI_State there is not a UI_LayoutCombo stack.
* UI_StyleTheme renamed to UI_StyleCombo
* UI_Theme has both UI_StyleCombo & UI_LayoutCombo
* Made files for the "project" related code
* ui_layout_compute moved to its own file, ui_layout now used for layout related data structures and interfacing
* Impovements to horizontal & vertical box impl
* UI_Box now keeps track of how many ancestors it has

code/ui_theme.odin

@@ -0,0 +1,54 @@
+package sectr
+
+UI_ThemePtr :: struct {
+	layout : ^UI_LayoutCombo,
+	style  : ^UI_StyleCombo,
+}
+
+UI_Theme :: struct {
+	layout : UI_LayoutCombo,
+	style  : UI_StyleCombo,
+}
+
+ui_theme_pop :: #force_inline proc() {
+	ui_layout_pop()
+	ui_style_pop()
+}
+
+@(deferred_none = ui_theme_pop)
+ui_theme_via_layout_style :: #force_inline proc( layout : UI_Layout, style : UI_Style ) {
+	using ui := get_state().ui_context
+	ui_layout_push( layout )
+	ui_style_push( style )
+}
+
+@(deferred_none = ui_theme_pop)
+ui_theme_via_combos :: #force_inline proc( layout : UI_LayoutCombo, style : UI_StyleCombo ) {
+	using ui := get_state().ui_context
+	ui_layout_push( layout )
+	ui_style_push( style )
+}
+
+@(deferred_none = ui_theme_pop)
+ui_theme_via_theme :: #force_inline proc( theme : UI_Theme ) {
+	using ui := get_state().ui_context
+	ui_layout_push( theme.layout )
+	ui_style_push( theme.style )
+}
+
+
+/*
+UI Themes: Comprise of UI_Box's layout & style
+
+Provides presets for themes and their interface for manipulating the combo stacks in UI_State in pairs
+*/
+
+UI_Theme_Btn_Default :: UI_Theme {
+
+}
+
+@(deferred_none = ui_layout_pop)
+ui_theme_btn_default :: #force_inline proc() {
+	ui_layout_push(UI_Theme_Btn_Default.layout)
+	ui_style_push(UI_Theme_Btn_Default.style)
+}