configure: Add -Wno-maybe-uninitialized to CFLAGS

The warnings generated by -Wmaybe-uninitialized are mostly spurious.
build: Do not let the install-cli target depend on a phony target

Real dependencies are preferable to phony ones where possible.
This also allows simplifying a recipe line with an automatic variable.
build: Coalesce some install recipe lines
build: Simplify phony target declaration with wildcards
build: Use 'DEPCC' for generating .depend, not 'CC'
cosmetic: Make .depend generation foreach loop more readable
build: Switch 'rm' to '$(RM)'
build: Split up 'install-lib-dev' into smaller subrecipes

'install-lib-headers' and 'install-lib-pc' now exist to handle
these particular tasks, allowing the use of automatic variables.
build: Use 'install-static' as a subrecipe for 'install-lib-static'

'lib-static' is now used only as the shortcut for default
build: Reorganize 'install-lib-shared'

*Use 'install-shared' as a subrecipe for 'install-lib-shared'
*Split 'lib-shared' into 'install-shared' and 'install-implib' so
 that automatic variables can be used. 'lib-shared' now only
 exists as the shortcut used by default
Add autotools-style silent build rules
build: Silence 'ln' when using silent rules
build: Use '$(INSTALL_DIR)' as alias for '$(INSTALL) -d'

Suppresses the echoing of directory-related INSTALL messages when
using silent rules