* Add render package
* Add text state
* Add more text operators
* Remove unnecessary files
* Add text font
* Add custom text render method
* Improve text rendering method
* Rename text state methods
* Refactor and document context interface
* Refact text begin/end operators
* Fix graphics state transformations
* Keep original font when doing font substitution
* Take page cropbox into account
* Revert to substitution font if original font measurement is 0
* Add font substitution package
* Implement addition transform.Point methods
* Use transform.Point in the image context package
* Remove unneeded functionality from the render image package
* Fix golint notices in the image rendering package
* Fix go vet notices in the render package
* Fix golint notices in the top-level render package
* Improve render context package documentation
* Document context text state struct.
* Document context text font struct.
* Minor logging improvements
* Add license disclaimer to the render package files
* Avoid using package aliases where possible
* Change style of section comments
* Adapt render package import style to follow the developer guide
* Improve documentation for the internal matrix implementation
* Update render package dependency versions
* Apply crop box post render
* Account for offseted media boxes
* Improve metrics of rendered characters
* Fix text matrix translation
* Change priority of fonts used for measuring rendered characters
* Skip invalid m and l operators on image rendering
* Small fix for v operator
* Fix rendered characters spacing issues
* Refactor naming of internal render packages
* Fixed PdfColorspaceSpecialIndexed.ImageToRGB() Fixes https://github.com/unidoc/unipdf/issues/258
* Fixed indexed colorspace bounds checking.
* Being super cautious to prevent a divide by zero error. I don't think the base cs can have <1 cpts.
* Updated image hash in extract_images_test.go to match new indexed colorspace code.
* add testfile from unipdf#258
* Add PdfFont method for encoding runes to charcode bytes
* Add getter method for CMap nbits
* Take CMap nbits into account when encoding text
* Adapt font test cases to include text encoding testing
* Add packed predefined cmaps
* Add cmap cid range parsing
* Load base cmap for predefined cmaps
* Refactor pdfFont to Unicode methods
* Preserve CharcodeBytesToUnicode behavior
* Add support for CID-keyed Type 0 fonts
* Add method documentation for the cmap package
* Refactor and document charcode to Unicode conversion code
* Add more cmap parsing test cases
* Add more method documentation in the cmap package.
* Remove unused code from the bcmaps package
* Improve cmap test case
* Assume identity when encoder is missing on regenerating field appearance
* Add missing encoder log message
* Add inverse CMap mappings
* Add CMap encoder
* Address golint notices and small fix in the cmap package
* Keep smaller charcodes when generating cmap inverse mappings
* Update extractor test case
* Keep latest supplement charcodes/CIDs when computing inverse mappings
* Fix comment typo
