Opdex Desktop 0.1.0-beta3

Additional fixes and improvements to app stability and indexing processes.

Changes:

• cde0ea6 indexing spacing adjustments, version bump
• 7fcbc54 github service connection
• c42ed05 indexing cirrus loading fix, tx feed refresh fix
• b022140 indexing background fixes, indexing checkpoint length reduction
• 296467a retry delay and srcForExactCrs bugfix
• 9341d09 QR icon and tx hash display on quote
• 8345bb0 allowance check bugfix
• 4ef33a8 indexer checkpoints (#9)
• 06c25bd StopMining method name typo
• 7b34ae7 adjust startup flags