4.1.0 RC-2

[mzieg]

• [#389] add Preset to metadata
• [#406] handle whitespace in developer path
• [#408] support --password cmd-line arg and ENLIGHTEN_PASSWORD environment variable
• [#420] allow user to navigate to target directory when saving exports
• [#426] support --max-thumbnails cmd-line arg and ENLIGHTEN_MAX_THUMBNAILS environment variable
• [#428] verify before overwriting files
• [#429] confirm when user configures "static" filename template
• [#431] validate interpolation inputs
• [#432] fixed scan averaging in BatchCollection
• [#446] update theming docs