feat(asm&go4k): Preprocess asm code using go text/template

The preprocessing is done sointu-cli and (almost) nothing is done by the NASM preprocessor anymore (some .strucs are still there.
Now, sointu-cli loads the .yml song, defines bunch of macros (go functions / variables) and passes the struct to text/template parses.
This a lot more powerful way to generate .asm code than trying to fight with the nasm preprocessor.

At the moment, tests pass but the repository is a bit of monster, as the library is still compiled using the old approach. Go should
generate the library also from the templates.

templates/output_sound.asm

@@ -0,0 +1,44 @@
+{{- if not .Output16Bit }}
+    {{- if not .Clip }}
+            mov     {{.DI}}, [{{.Stack "OutputBufPtr"}}] ; edi containts ptr
+            mov     {{.SI}}, {{.PTRWORD}} su_synth_obj + su_synthworkspace.left
+            movsd   ; copy left channel to output buffer
+            movsd   ; copy right channel to output buffer
+            mov     [{{.Stack "OutputBufPtr"}}], {{.DI}} ; save back the updated ptr
+            lea     {{.DI}}, [{{.SI}}-8]
+            xor     eax, eax
+            stosd   ; clear left channel so the VM is ready to write them again
+            stosd   ; clear right channel so the VM is ready to write them again
+    {{ else }}
+            mov     {{.SI}}, qword [{{.Stack "OutputBufPtr"}}] ; esi points to the output buffer
+            xor     ecx,ecx
+            xor     eax,eax
+            %%loop: ; loop over two channels, left & right
+             do fld     dword [,su_synth_obj+su_synthworkspace.left,_CX*4,]
+                {{.Call "su_clip"}}
+                fstp    dword [_SI]
+             do mov     dword [,su_synth_obj+su_synthworkspace.left,_CX*4,{],eax} ; clear the sample so the VM is ready to write it
+                add     _SI,4
+                cmp     ecx,2
+                jl      %%loop
+            mov     dword [_SP+su_stack.bufferptr - su_stack.output_sound], _SI ; save esi back to stack
+    {{ end }}
+{{- else}}
+            mov     {{.SI}}, [{{.Stack "OutputBufPtr"}}] ; esi points to the output buffer
+            mov     {{.DI}}, {{.PTRWORD}} su_synth_obj+su_synthworkspace.left
+            mov     ecx, 2
+            output_sound16bit_loop: ; loop over two channels, left & right
+                    fld     dword [{{.DI}}]
+                    {{.Call "su_clip"}}
+            {{- .Float 32767.0 | .Prepare | indent 16}}
+                    fmul    dword [{{.Float 32767.0 | .Use}}]
+                    push    {{.AX}}
+                    fistp   dword [{{.SP}}]
+                    pop     {{.AX}}
+                    mov     word [{{.SI}}],ax   ; // store integer converted right sample
+                    xor     eax,eax
+                    stosd
+                    add     {{.SI}},2
+                    loop    output_sound16bit_loop
+            mov     [{{.Stack "OutputBufPtr"}}], {{.SI}} ; save esi back to stack
+{{- end }}