v0.4.0

The main new features/fixes of v0.4.0 are:

• Extended SiteSelectors to allow specifying indices and exclusions (not): #84, #97
• The range in HopSelector can now be an interval, and defaults to nearest neightbor distance: #87, #88, #89
• Introduced KetModels, based on SiteSelectors for use in KPM: #80, #99
• Reworked unitcell/supercell functionality to integrate with SiteSelectors: #79, #98
• Fixed wrap: #81
• Ability to change lattices with lattice(lat; kw...) (e.g. change Bravais vectors): #94, #95
• similarmatrix(h, flatten) now allocates a flattened version of h's matrix for bloch!: #106
• Removed need to optimize! Hamiltonians: #106
• Maintenance and improvements of plot backends: #90, #91, #96, #102, #108, #109
• Overhauled bandstructure functionality (DualNumbers, parametric mappings, linecuts, isometric transforms...): #100, #101, #107