Skoolkit

* Made the image writer component pluggable
* Added support for defining groups of entries (via the `[EntryGroups]` section of the ref file) whose disassembly pages can be given custom titles and headers
* Added the `Address` parameter to the `[Game]` section (for specifying the format of address fields on disassembly pages and memory map pages, and of the default link text for the `R` macro)
* Added the `Length` parameter to the `[Game]` section (for specifying the format of the new length attribute of entry objects in HTML templates, which is now used instead of size in the Length column on memory map pages)
* Added the `Peek` and `Word` configuration parameters for `snapinfo.py` (for specifying the format of each line of the output produced by the `--peek` and `--word` options)
* Added support for specifying an `expand` directive value over multiple lines by prefixing the second and subsequent lines with `+`
* Added support to the `--ram` option of `tap2sna.py` for the `sysvars` operation (for initialising the system variables in a snapshot)
* Changed the default value of the `DefmSize` configuration parameter for `sna2skool.py` from 66 to 65; this makes it compliant with the default maximum line width of 79 defined by the `LineWidth` configuration parameter
* Fixed the bug that prevents instruction comments from being repeated in a control file loop
* Fixed the bug that makes `sna2skool.py` ignore a given start address below 16384 when converting a snapshot

* Added the `PLOT` macro (for setting, resetting or flipping a pixel in a frame already created by an image macro)
* Added the `--begin` option to `bin2tap.py` (for specifying the address at which to begin conversion)
* The `--end` option of `bin2tap.py` now applies to raw memory files as well as SNA, SZX and Z80 snapshots
* Added the `--data` option to `tapinfo.py` (for showing the entire contents of header and data blocks)
* Added support to the `--ctl` option of `sna2skool.py` and `snapinfo.py` for reading control files from a directory
* Added the `x` and `y` parameters to the frame specification of the `UDGARRAY*` macro (for specifying the coordinates at which to render a frame of an animated image)
* Added support for replacement fields in the `args` parameter of the `CALL` macro, in the integer parameters of the `CHR`, `D`, `INCLUDE`, `N`, `POKES`, `R` and `SPACE` macros, and in the integer parameters and cropping specification of the `FONT`, `SCR`, `UDG` and `UDGARRAY` macros
* Fixed the bug that causes ‘e+1’ to be interpreted as a floating point number when it appears in a BASIC program

* Added the `--call-graph` option to `snapinfo.py` (for generating a call graph in DOT format)
* Added the `--ctl` option to `snapinfo.py` (for specifying a control file to use when generating a call graph)
* Added the `--org` option to `snapinfo.py` along with the ability to read binary (raw memory) files
* Added support to `snapinfo.py` for reading configuration from *skoolkit.ini*
* Added the `--ini` and `--show-config` options to `snapinfo.py` (for setting the value of a configuration parameter and for showing all configuration parameter values)
* Added the `DEFINE` macro (for defining new skool macros)
* Added the `LET` macro (for defining variables that can be retrieved by other macros via replacement fields)
* Added the `FORMAT` macro (for performing a Python-style string formatting operation on an arbitrary piece of text)
* Added the `expand` directive (for specifying skool macros to be expanded during ASM writer or HTML writer initialisation)
* Added the `tindex` parameter to the `FONT`, `SCR`, `UDG` and `UDGARRAY` macros (for specifying a transparent colour to use other than the default)
* Added the `alpha` parameter to the `FONT`, `SCR`, `UDG` and `UDGARRAY` macros (for specifying the alpha value to use for the transparent colour)
* Added the `refs` directive (for managing the addresses of routines that jump to or call an entry point)
* Added support for replacement fields in the integer parameters of the `FOR` and `PEEK` macros
* Added the `--page` option to `snapinfo.py` (for specifying the page of a 128K snapshot to map to 49152-65535)