- Replace strdup(s) with cfg_strdup(funname, s) that exits on out of mem
- Replace malloc(n) with cfg_malloc(funname, n) that exits on out of mem
- Change multiline string scanning in lexer.l to avoid core dump
- Remove global variables string_buf and string_bug_ptr
- Ensure reading strings unescapes strings C-Style
- Ensure writing strings escapes strings C-Style again
Commit looks longer than needed as unescape() and auxiliary functions needed
to be moved from term.c (not in libavrdude) to config.c (in libavrdude).
Also changed usbdev, usbsn, usbvendor and usbproduct components from
PROGRAMMER structure to be cached string pointers rather than fixed-size
arrays. These will be initialised by pgm_new() with a pointer to nul;
Some 90% of the space of AVRPART and some 50% of PROGRAMMER is occupied by a
4 kB array config_file[] that contains the configuration file name. In
preparation of developer options that output a raw dump of the part
descriptions, this commit changes the config_file components from a large
array, which is duplicated in each part and programmer description, to a
cached string for each config file allowing for smaller raw dumps.
This commit also changes the config file name to its realpath(), eg, shortens
unwarranted `/bin/../etc/` file name components. It also changes the global
variable names `infile` and `fileno` to cfg_infile and cfg_fileno for an ever
so slight improvement of code clarity.