Bump MainArgs to 0.6.1

[lihaoyi]

Also updated the bash launchers' special casing of -i to allow for it to be part of a combined token, as long as the combined token starts with -i

With the installLocalCacheed version of Mill, I can now run:

$ ./mill -ikw contrib.__.compile

and the flags -i, -k, and -w will all take effect independently

The auto-kebab-case name mapping applies to Mill's own CLI args, the args of user-defined T.commands, but not the names of the target/command themselves. e.g. you can call;

• ./mill --noServer core.ivyDepsTree --withCompile --withRuntime or
• ./mill --no-server core.ivyDepsTree --with-compile --with-runtime

but you cannot call

• ./mill --no-server core.ivy-deps-tree --with-compile --with-runtime

It should be easy to add name-mapping for the target selector as well, or I could also disable the name-mapping for user-define command arguments if we decide that's not the right thing to do. I'm not sure TBH what the right thing to do here is; bash naming conventions is fundamentally incompatible with Scala naming conventions, so regardless what Mill decides there will be some inconsistencies between:

• Bash naming conventions
• Mill's own CLI flag naming conventions
• Mill CLI task naming conventions
• Mill CLI command argument naming conventions
• Mill Scala object/method naming conventions
• Mill Scala method argument naming conventions
• Scala object/method naming conventions
• Scala method argument naming conventions

I guess it just depend where we want to draw the line and tolerate the inconsistency. I feel like maybe something like ./mill --no-server core.ivy-deps-tree --with-compile --with-runtime would be the ideal outcome, where everything in Bash-land is consistent and everything in Scala-land is consistent.

Pull request: #2990

[lihaoyi]

Not sure why this is necessary, something about type inference must have changed in 0.6.0 to make it source incompatible (even though it's binary compatible)

[lefou]

Seems, bumping the version to 0.6.0 was the right move.