Builder: Standard segment names

You are free to invent your own segment names for use with Builder. The only exception is that there is one special, predefined segment called -UNAMED- which captures anything in your source files that appears before a <...> segment tag and emits them first.

In any library functions that we make we will stick as far as possible to the following list of names. It's a good idea if you use the same names for corresponding function.

`DOCCOSEG`	Contains any documentation on how to use a library file. `DISCARD` from your builds
`IOSEG`	Input and output assignments, including analogs
`CONSTSEG`	Constant values, for example time intervals
`MEQUSEG`	Contains any mEQU RAM allocations (say for PermStore). Must appear before any `defBYTE`, `defFloat`, `defSEM` etc automatic RAM allocations.
`DEFSEG`	Contains automatic RAM allocations `defBYTE`, `defSEM` etc. use this only if your prefer (stylistically) to have all your RAM allocations near the start of your program.
`TESTSEG`	Test code that should always be `DISCARD`ed from production builds
`INITSEG`	Initialize code - stuff that should run once at startup. Generally calls initialize routines for various modules/objects.
`LAUNCHSEG`	Contains a `RunTasksForever` to start up MultiTrack. Should be used in .b1d files with `ONEONLY`
`CODESEG`	Actual active code. May also contain defXXX memory allocations if you prefer having them inside the module that owns them (c.f. near the top of your program.)
`NVEM0DIR`	Contains a `NVEM0` directive. Should be used in .b1d files with `ONEONLY` Must appear before any other NVEM related segment.
`NVEM0DATA`	Contains NVEM page 0 tables or data.
`XWIREINIT`	Contains an instruction (typically `XwireMaster XwireTab)` that will start up Xwire using the configuration data located under the label `XwireTab` in NVEM0. Should be used in .b1d files with `ONCEINLINE.` Used by any of our library of Active Template modules that use Xwire.
`XWIREMTAB`	Contains the line label (typically `XwireTab)`in NVEM0 that signals the Xwire configuration table. Should be used in .b1d files with `ONEONLY.` Used by any of our library of Active Template modules that use Xwire.
`XWIREMDATA`	Contains configuration data, in NVEM0, for Xwire master operation. Used by any of our library of Active Template modules that use Xwire.
`XWIREMEND`	Contains an end of table sentinel for Xwire master configuration data. Should be used in .b1d files with `ONEONLY`. Used by any of our library of Active Template modules that use Xwire
`DEBUG1`	Only ever used in `<=IF` tags. If enabled switches on debug features to help you debug your system.
`DEBUG2`	Only ever used in `<=IF` tags. If enabled switches on debug features to help you debug your system.
`DEBUG3`	Only ever used in `<=IF` tags. If enabled switches on debug features to help you debug your system.

Note that Builder will raise an error if there is a segment name in a .spt file that is not listed in the .b1d file, i.e. you must explicitly DISCARD unwanted segments. The inverse is not the case: you can have segment names in the .b1d file that do not exist in any .spt file.