Successfully use my custom PDF view in XML layout
In mupdf.c:
 * Remove unused fields (for alerts)
 * Remove consideration for interactive doc in MuPDF_drawPage
 * Remove MuPDF_updatePageInternal since there is need for partial page redraw (probably only used for interactive document)
 * Remove other unused functions in mupdf.c
 * Change definition of LOG* macros: wrap with `if (DEBUG) { }`