Reduce verbosity of --appimage-extract

Merge pull request AppImage#359 from orivej/build-debug

Support debug build

Merge pull request AppImage#354 from darealshinji/patch-1

avoid unneeded if-statements, initializer fixes

getsection: make use of Elf32_Ehdr and Elf32_Shdr on 32-bit systems (A…

…ppImage#308)

Using the 64-bit counter parts causes the location of the embedded ELF
section for `--updateinformation` to be calculated incorrectly, and
eventually causing a segmentation fault.

Notice this commit relies on GCC specific defines (`__i386__`), and
defaults to 64-bit if 32-bit was not detected.

See: AppImage#307
Signed-off-by: Juan Cruz Viotti <[email protected]>

Decrease verbosity, no false alarms

Overwrite $APPIMAGE and $APPDIR if they already exist, closes AppImag…

…e#66

Revert "Added wizardless commands (pack and unpack)" and re-implement…

… original solution; add USAGE

Update AppRun.c

Update runtime.c

Update README.md