amark: add __DEBUG__ macro

  since amark is enough hidden, it's difficult to remove/remplace
amark: add disable_wp & restore_wp

 These two utility functions enable/disabled WP without trigger
 scheduling race condition.
 It taken from PaX project, see:
 http://vulnfactory.org/blog/2011/08/12/wp-safe-or-not/
amark: update __DEBUG__ macro
amark: add Push/Retn before the legit-syscall prologue to hijack it

 instead of overwrite the sys_call_table entry for the syscall targeted,
 we use a Push/Retn method:
 We insert an indirect jump at the beginning of the sys_call who jump
 into our malicious function.
 The integrity of the sys_call_table is preserved, this has for effect
 to bypass volatility linux_check_syscall module
amark: various cosmetic fix
amark: add junk dead code in our opcode injection

  we use jiffies to get some RN's values.
  with this commit, it's more difficult to detect that the syscall
  is hijacked.
  Previously, we have to just find 0x68 and 0xc3 opcode consecutive
  spearate by 4bytes at the start of the syscall.
amark: cosmetic alignment
Add README, TODO