Cyberfox Beta 48.0b6

Whats New:

• Fixed: Passed patch for Bug 1257554 - [e10s] Remove restore on demand checkbox.
• Refactor cyberfox included theme files.
• Added: Patch for Bug 1269244 - crash in nhasusstrixosd.dll@0x663e
• Update: CyberCTR to 1.5.6b3
• Merge: cyberfox 48.0b6 with cyberfox 48.0b5
• Update: install_cyberfox.sh to version 1.4
• Update Pl (Polish) installer localization (Thanks @hawkeye116477)

Full change list