replace strings in ELF .rodata sections

[ahgamut]

With tool/build/renamestr (or an equivalent feature), I hope to avoid the /zip folder when building binaries with https://github.com/ahgamut/superconfigure. Most of the folder locations involving /zip are stored in the .rodata section of the ELF binary, and /zip is more useful for the APE than the debug ELF binaries.

The current build process on superconfigure involves:

• create a /zip folder using sudo
• any config data that a binary requires (terminfo entries, SSL certs) is copied to /zip
• debug binaries use the actual /zip folder (or crash)

With this PR, the build process hopefully becomes:

• no need to create a /zip folder with sudo
• install config data to the usual location( $LOCATION/superconfigure/cosmos/$ARCH/$SUBFOLDER)
• run renamestr on the ELF binary to replace $LOCATION/superconfigure/cosmos/$ARCH/ to /zip, before running apelink
• now debug binaries will work like regular ELF binaries built on a Linux system

Perhaps this feature can be part of apelink itself (the structure and some code of renamestr is copied from apelink), but I wrote a separate tool in a draft PR, for an initial exploration.

[ahgamut]

Have confirmed that renamestr avoids the use of /zip for building bash and berry in superconfigure:

(There is a build error relating to the installation of terminfo entries, but I assume that is due my system interfering with the ncurses build process).