Log Message:
tex-circuitikz{,-doc}: update to 1.6.7

Several new blocks, more flexible generic anchors for blocks,
and a new option to align the signs on American-style voltage
sources.

- Added `saturation` block
- Added `iamp`, `sigmoid`, and `allornothing` blocks
- Added optical fiber `fiber` block
- Now, the position of the lateral anchors (`left up` and similar)
  of blocks is configurable
- Now you can choose how the signs on American-style sources
  rotate when the source is not vertical
- A new section in the manual about related packages