Use flash algorithm, add linker sections, remove erase_all

[9names]

Builds on #19, but turns off default features of flash_algorithm to allow removal of the unimplemented erase_all function.

Resolves #14 by added the requisite sections.

$ python scripts/generate_blobs.py ~/flash-algo/target/thumbv6m-none-eabi/release/flash-algo
Flash Device:
  name=b''
  version=0x0
  type=5
  start=0x10000000
  size=0x1000000
  page_size=0x100
  value_empty=0xff
  prog_timeout_ms=1000
  erase_timeout_ms=2000
  sectors:
    start=0x10000000, size=0x1000

$ arm-none-eabi-objdump -h target/thumbv6m-none-eabi/release/flash-algo

target/thumbv6m-none-eabi/release/flash-algo:     file format elf32-littlearm

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 PrgCode       000001c0  00000000  00000000  000000b4  2**2
                  CONTENTS, ALLOC, LOAD, CODE
  1 PrgData       00000004  000001c0  000001c0  00000274  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  2 DevDscr       000000b0  000001c4  000001c4  00000278  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
                  
$ arm-none-eabi-objdump -t target/thumbv6m-none-eabi/release/flash-algo

target/thumbv6m-none-eabi/release/flash-algo:     file format elf32-littlearm

SYMBOL TABLE:
00000000 l    df *ABS*  00000000 flash_algo.a9f41f0df4cef4a-cgu.0
000001a0 l     F PrgCode        00000008 _ZN4core9panicking9panic_fmt17hd2523d0706fb7bbcE
000001a8 l     O PrgCode        00000001 _ZN10flash_algo8_IS_INIT17h3b044e184bd717b2E.0
000001b8 l     O PrgCode        00000004 _ZN10flash_algo14_ALGO_INSTANCE17hefe569ff8b9fd3c4E.4
000001bc l     O PrgCode        00000004 _ZN10flash_algo14_ALGO_INSTANCE17hefe569ff8b9fd3c4E.5
000001b0 l     O PrgCode        00000004 _ZN10flash_algo14_ALGO_INSTANCE17hefe569ff8b9fd3c4E.2
000001ac l     O PrgCode        00000004 _ZN10flash_algo14_ALGO_INSTANCE17hefe569ff8b9fd3c4E.0
000001b4 l     O PrgCode        00000004 _ZN10flash_algo14_ALGO_INSTANCE17hefe569ff8b9fd3c4E.3
00000138 g     F PrgCode        00000034 EraseSector
000001c4 g     O DevDscr        000000b0 FlashDevice
00000000 g     F PrgCode        00000104 Init
000001c0 g     O PrgData        00000004 PRGDATA_Start
0000016c g     F PrgCode        00000034 ProgramPage
00000104 g     F PrgCode        00000034 UnInit

[9names]

Going to pull the parts of this into different PRs