Refine preconfigured page break point logic

What's Changed

• version 0.2.1. # fix slough pre by @mettta in #103
• Mask: update and enable Content Flow masking by @mettta in #104
• Masking by @mettta in #105
• Preserve glyph bleed and visual spillover in header/footer mask regions by @mettta in #106
• Improve finding the page break point by @mettta in #113
• 0.2.2 by @mettta in #114
• test/end2end: findBetterPageStart: do not assert on the page number by @stanislaw in #115
• Node, Pages: findBetterForcedPageStarter() - Refine preconfigured page break point by re-evaluating first-child condition when a non-hanging left neighbor is found • by @mettta in #116
• 0.2.3 by @mettta in #117

Full Changelog: v0.2.1...v0.2.3