UI/API changes

• NEW: Measurement form: auto-top-up settings
• NEW: Measurement details manage tab: auto-top-up settings and manual top-up (when possible)
• CHANGES: Khipu (beta): Horizontal layout mode, much improved RTT mode with anomaly notes, country filter dropdown, country view lookup/scoring, IP labels in IP view
• CHANGE: Anchor list now includes 'Written off' status
• CHANGE: Quick measurements (QuickLook, QuickKhipu) now use 100 probes for every msm the make
• CHANGE: Legal accordion now searchable
• FIX: Measurement form error when using an existing measurement for selecting probes
• FIX: Colons being removed from IPv6 because of overzealous sanitisation
• FIX: Standardise boolean value display in measurement details
• FIX: Measurement form: can't select start date from picker
• TWEAK: Anchor details tab empty table message
• TWEAK: Make coverage map resizable
• TWEAK: Improve responsiveness/accuracy of streamed results in quick msms