New features for text searching and more

This resolves

• #575
• #697
• #691

and removes the hit_max parameter from text searching. In addition, hyphenated words around line breaks are still found.

The use of the clip parameter in text searches and text extractions now only includes characters whose bboxes are fully contained in the clip rctangle.

Important fixes, some improvements for drawing extraction

• fixed #692
• fixed #686
• Added transparency options for various methods in classes Shape and Page.

Support MuPDF v1.18.0

This version fixes the following issues:

• #519 - method Page.cleanContents() should no longer destroy the PDF page's appearance. In earlier versions, this upstream bug occurred in rare cases.
• #675 - unsuccessful storage allocations (e.g. for extremely large pixmaps), could occasionally lead to interpreter crashes. This should now always be prevented (fingers crossed).
• #668 - the specification of line dashes in PDF is now correctly documented.
• #669 - fixed a major cause of memory leakage in method Document.insertPDF.

The following new features or improvements are included:

• Text extraction method Page.getText() now also works for annotations: Annot.getText().
• Text from within a rectangle can now be extracted directly via Page.getTextbox(rect). This may obsolete extra scripts in many cases.
• When applying redactions on PDF pages, the handling of images can now be fine-controlled via a new parameter.
• The DPI (resolution) of PNG images created from pixmaps is now automatically set from the Pixmap.xres and Pixmap.yres values.

Fixes, performance improvements

Fixed #651
Fixed #645
Fixed #622
Fixed #653
Fixed #640
Added methods and atrributes to speed up TOC maintenance.
Added new page method to extract text from inside a rectangle.
All getText() methods (except (X)HTML and XML) now support a clip parameter.

Bug fixes and more support for font replacements

• Fixed #605
• Fixed #600
• Added origin key to text span dictionary of Page.getText("dict").
• Added property buffer to fitz.Font.
• Added option sanitize to Page.cleanContents().

Several fixes

• Fixes #561
• Fixes #566
• Fixes #568
• Correct use of opacity default in TextWriter.writeText().
• Supporting fonts of [pymupdf-fonts(https://github.com/pymupdf/pymupdf-fonts).
• Some smaller feature improvements.

Font Handling improvements and other fixes

Fixes #561 - more than 10 TextWriter fonts per page
Fixes #562 - annotation pixmaps no longer derived from tha page
Fixes wrong appearance of mono-spaced fonts
Resolves #563 - allow manipulation of PDF property NeedAppearances
Support optional fonts provided via repository pymupdf-fonts

Minor Fixes, more flexible TextWriter Textbox

Fixes #540
Fixes #548
TextWriter.fillTextbox now supports indenting start of text.

Fix Important issue

Fixes #533
Adds appearance flexibility to redactions annotations, #535.

Addressing minor bugs

Fixed: #525, #520
Implemented: #524

Improved interactive help a lot.