pdf2htmlEX-Android v0.18.19

• Update NDK to 23.2.8568313 (last to support sdk level 16)

• Remove deprecated pdf2htmlEX_exe interface.
  pdf2htmlEX_exe had to be removed, because it required pdf2htmlEX (not -Android) to be built as a shared library.
  pdf2htmlEX (not -Android) built as a static library can be included in pdf2htmlEX-Android.so, which allows optimizing a lot of unused code away.
  Shared library version was ~14 megs, static library version is ~7 megs.

• Remove deprecated NoForking mode

• Add BuildConfig.VERSION_NAME

• Implement public static String generateOutputFilename(String inputFilename), which removes .pdf suffix and adds .html suffix.

Rename following parameters:

• setOutline to setProcessOutline
• setBackgroundFormat to setBackgroundImageFormat

Expose following upstream pdf2htmlEX parameters to downstream users:

• setOutputHtml
• setFirstPage
• setLastPage
• setZoomRatio
• setFitWidth
• setFitHeight
• setUseCropBox
• setDPI
• setEmbedCSS
• setEmbedFont
• setEmbedImage
• setEmbedJavascript
• setEmbedOutline
• setSplitPages
• setProcessNonText
• setProcessOutline
• setProcessAnnotation
• setProcessForm
• setPrinting
• setFallback
• setEmbedExternalFont
• setFontFormat
• setDecomposeLigature
• setAutoHint
• setStretchNarrowGlyph
• setSqueezeWideGlyph
• setOverrideFstype
• setProcessType3
• setHorizontalEpsilon
• setVerticalEpsilon
• setSpaceThreshold
• setFontSizeMultiplier
• setSpaceAsOffset
• setToUnicode
• setOptimizeText
• setCorrectTextVisibility
• setCoveredTextDPI
• setBackgroundImageFormat
• setSVGNodeCountLimit
• setDebug
• setProof
• setQuiet